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LEGO Missing Piece Checker

Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece and leave with the element ID LEGO asks for, or a link to buy the part.

Robobots

Checking

4099 Robobots

326 pieces in 146 part and color combinations.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

Look-alike colors in this set

These parts appear in this set in two colors that are easy to confuse. If you are one short in one color, check whether it went in where the other color belongs. Each color has its own element ID in the parts list at the back of the instructions.

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Piece checklist

Blue 101 pieces

  • Bracket 1 x 2 - 1 x 4 [Square Corners] Blue Part 2436 Element 4282744 or 4189120 ×4
  • Brick 2 x 2 Blue Part 3003 Element 4103589 or 300373 ×2
  • Brick 2 x 2 Corner Blue Part 2357 Element 4558606 or 4533323 ×2
  • Brick Curved 1 x 2 x 1 1/3 with Curved Top Blue Part 6091 Element 6347945 or 4519981 ×4
  • Brick Curved 2 x 3 Blue Part 6215 Element 621523 ×2
  • Brick Sloped 33° 3 x 1 Blue Part 4286 Element 428623 ×4
  • Brick Sloped 45° 2 x 2 Blue Part 3039 Element 303923 ×4
  • Brick Sloped 45° 3 x 4 Double / 33° Blue Part 4861 Element 4512826 or 4187744 ×1
  • Brick Sloped 65° 2 x 2 x 2 Smooth without Bottom Tube Blue Part 3678a Element 4129792 or 367823 ×1
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] Blue Part 3660 Element 366023 ×3
  • Brick Sloped Inverted 45° 4 x 2 Double with 2 x 2 Recessed Blue Part 4871 Element 4656767 or 4189119 ×1
  • Brick Special 1 x 1 with Headlight Blue Part 4070 Element 407023 ×4
  • Brick Wedged, Sloped 4 x 2 Triple Left Blue Part 43710 Element 4622180 or 4180410 ×2
  • Brick Wedged, Sloped 4 x 2 Triple Right Blue Part 43711 Element 4622179 or 4180420 ×2
  • Hinge Brick 1 x 2 Locking with 2 Fingers Vertical End, 9 Teeth Blue Part 30365 Element 4495735 or 4187772 ×4
  • Hinge Brick 1 x 2 Top Plate Thin Blue Part 3938 Element 4279389 or 393823 ×2
  • Hinge Plate 1 x 4 Swivel Top / Base - Solid Clip [Complete Assembly] Blue Part 73983 Element 6102759 or 4119371 ×2
  • Plate 1 x 2 Blue Part 3023 Element 302323 ×4
  • Plate 1 x 4 Blue Part 3710 Element 371023 ×6
  • Plate 1 x 6 Blue Part 3666 Element 366623 ×1
  • Plate 2 x 2 Blue Part 3022 Element 4613973 or 302223 ×2
  • Plate 2 x 2 Corner Blue Part 2420 Element 242073 or 242023 ×2
  • Plate 2 x 3 Blue Part 3021 Element 302123 ×9
  • Plate 2 x 4 Blue Part 3020 Element 4240375 or 302023 ×8
  • Plate 2 x 6 Blue Part 3795 Element 379523 ×1
  • Plate Special 1 x 1 with Clip Light, Bar Hole [Thick Ring] Blue Part 4081b Element 6281991 or 4632567 ×2
  • Plate Special 1 x 1 with Clip Vertical [Thick U Clip] Blue Part 4085c Element 408523 ×1
  • Plate Special 1 x 2 with Handles [Flat Ends / Low Attachment] Blue Part 3839b Element 4286615 or 383923 ×2
  • Plate Special 2 x 2 with Grills Blue Part 41862 Element 4163546 ×1
  • Plate Special 3 x 2 with Rounded End, Hole Blue Part 3176 Element 317673 or 317623 ×2
  • Technic Brick 1 x 2 [1 Pin Hole] Blue Part 3700 Element 370023 ×3
  • Technic Plate 2 x 6 [5 Holes] Blue Part 32001 Element 4114027 or 3200123 ×1
  • Tile 1 x 2 with Groove Blue Part 3069b Element 306923 ×2
  • Tile 1 x 4 with Groove Blue Part 2431 Element 243123 ×2
  • Tile 2 x 2 with Groove Blue Part 3068b Element 306823 ×3
  • Turntable 2 x 2 Plate, Base Blue Part 3680 Element 368023 ×1
  • Wedge Plate 3 x 4 without Stud Notches Blue Part 4859 ×4

Black 49 pieces

  • Brick Round 1 x 1 Open Stud Black Part 3062b Element 306226 ×2
  • Dish 6 x 6 Inverted, Radar / Webbed [Anti-studs at 90°] Black Part 4285b Element 6603362 or 4509865 ×1
  • Engine - Smooth, Small 1 x 2 Side Plate [With Axle Holders] Black Part 3475b Element 347526 ×2
  • Equipment Camera with Side Sight [aka Space Gun] Black Part 4360 Element 436026 ×1
  • Hinge Brick 1 x 2 Base Black Part 3937 Element 393726 ×2
  • Hinge Brick 1 x 2 Locking with 2 Fingers Horizontal End, 9 Teeth Black Part 30540 Element 4144533 ×2
  • Hinge Cylinder 1 x 3 Locking with 1 Finger and 2 Fingers On Ends, without Hole, 9 Teeth Black Part 30554a ×4
  • Hinge Cylinder 1 x 3 Locking with 1 Finger and Technic Friction Pin with Round Hole Black Part 41532 Element 4159335 ×4
  • Hinge Plate 1 x 2 Locking with 1 Finger On Top Black Part 30383 Element 6338799 or 4144575 ×4
  • Hinge Plate 1 x 4 Swivel Top / Base - Solid Clip [Complete Assembly] Black Part 73983 Element 6102782 or 74011 ×2
  • Plate 1 x 2 Black Part 3023 Element 302326 ×4
  • Plate 2 x 3 Black Part 3021 Element 302126 ×3
  • Plate 2 x 8 Black Part 3034 Element 303426 ×2
  • Plate Special 1 x 1 with Clip Light, Bar Hole [Thick Ring] Black Part 4081b Element 6281993 or 4632571 ×2
  • Plate Special 1 x 1 with Clip Vertical [Thick U Clip] Black Part 4085c Element 408526 ×2
  • Plate Special 1 x 2 with Handles [Flat Ends / Low Attachment] Black Part 3839b Element 383926 ×3
  • Technic Plate 2 x 4 [3 Holes] Black Part 3709 Element 370926 ×1
  • Tile Special 1 x 2 Grille with Bottom Groove Black Part 2412b Element 241226 ×3
  • Wedge Plate 3 x 4 without Stud Notches Black Part 4859 ×2
  • Wedge Plate 4 x 4 with 2 x 2 Cutout Black Part 43719 Element 6275401 or 4561035 ×2
  • Wedge Plate 4 x 6 Cut Corners Black Part 32059 Element 4129572 ×1

Dark Gray 46 pieces

  • Brick Sloped 45° 2 x 1 Double / Inverted with Hollow Bottom Dark Gray Part 3049c Element 4120159 ×2
  • Brick Sloped 45° 2 x 1 with Bottom Pin Dark Gray Part 3040b Element 4121970 or 4109985 ×4
  • Brick Sloped 45° 3 x 4 Double / 33° Dark Gray Part 4861 Element 4187746 or 486127 ×2
  • Brick Sloped Inverted 45° 2 x 2 Double Convex Dark Gray Part 3676 Element 4179421 or 367627 ×2
  • Brick Special 1 x 1 with 3 Speakers / Loudspeakers / Space Positioning Rockets Dark Gray Part 3963 Element 4187745 or 396327 ×2
  • Brick Special 1 x 4 with 4 Studs on One Side Dark Gray Part 30414 Element 4144532 ×3
  • Brick Wedged, Sloped 4 x 4 Triple, Stud Notches Dark Gray Part 48933 Element 4234721 or 4222980 ×2
  • Brick Wedged, Sloped 45° 4 x 2 Left Dark Gray Part 43721 Element 4180519 ×2
  • Brick Wedged, Sloped 45° 4 x 2 Right Dark Gray Part 43720 Element 4180527 ×2
  • Brick Wedged, Sloped Inverted 4 x 4 Triple [2 Connections between Front Studs] Dark Gray Part 4855 Element 4187769 or 4120396 ×1
  • Cone 1 x 1 [No Top Groove] Dark Gray Part 4589 Element 4125260 or 458927 ×2
  • Hinge Brick 1 x 2 Locking with 2 Fingers Vertical End, 9 Teeth Dark Gray Part 30365 Element 4144501 or 4125291 ×2
  • Plate 1 x 2 Dark Gray Part 3023 Element 4111983 or 302327 ×1
  • Plate 1 x 4 Dark Gray Part 3710 Element 371027 ×1
  • Plate 2 x 2 Dark Gray Part 3022 Element 4114003 or 302227 ×1
  • Plate 2 x 3 Dark Gray Part 3021 Element 4108041 or 302127 ×3
  • Plate 2 x 4 Dark Gray Part 3020 Element 4112232 or 302027 ×4
  • Plate 4 x 4 Dark Gray Part 3031 Element 4243823 or 4113911 ×1
  • Plate Round 1 x 1 with Solid Stud Dark Gray Part 6141 Element 4124087 or 614127 1 spare in the box ×2
  • Plate Special 1 x 1 with Clip Light, Bar Hole [Thick Ring] Dark Gray Part 4081b Element 4169162 or 408127 ×2
  • Plate Special 1 x 2 Side Handle [Free Ends] Dark Gray Part 2540 Element 4140589 or 4109721 ×1
  • Plate Special 2 x 2 with Bar Frame Octagonal Dark Gray Part 30033 Element 3003327 ×2
  • Plate Special 2 x 2 with Grills Dark Gray Part 41862 Element 4163164 ×1
  • Technic Brick 1 x 2 [1 Pin Hole] Dark Gray Part 3700 Element 4114529 or 370027 ×1

Light Gray 46 pieces

  • Brick Round 2 x 2 Dome Top, Blocked Open Stud, Bottom Axle Holder Light Gray Part 30367b Element 4216650 ×1
  • Brick Special 2 x 4, with 2 x 2 Brick with Top Pin and 1 x 2 Side Plates Light Gray Part 30592 Element 4143056 ×1
  • Hinge Brick 1 x 2 Locking with 1 Finger Vertical End and 2 Fingers Vertical End, 9 Teeth Light Gray Part 30386 Element 4143133 ×4
  • Hinge Brick 1 x 4 Locking with 1 Finger Vertical End and 2 Fingers Vertical End, 9 Teeth Light Gray Part 30387 Element 4144571 or 4142993 ×4
  • Hinge Brick 2 x 2 Locking with 1 Finger Vertical and Axle Hole [X Opening] Light Gray Part 30389c Element 4163900 or 4144507 ×1
  • Hinge Plate 1 x 2 Locking with 1 Finger On End, with Groove Light Gray Part 44301a Element 4183037 ×4
  • Hinge Plate 1 x 2 Locking with 2 Fingers On End, with Groove, 9 Teeth Light Gray Part 44302a Element 4183049 ×4
  • Plate 1 x 1 Light Gray Part 3024 Element 302402 ×2
  • Plate 1 x 2 Light Gray Part 3023 Element 302302 ×2
  • Plate 1 x 4 Light Gray Part 3710 Element 371002 ×1
  • Plate 2 x 2 Light Gray Part 3022 Element 302202 ×2
  • Plate 2 x 2 Corner Light Gray Part 2420 Element 242052 or 242002 ×2
  • Plate 2 x 6 Light Gray Part 3795 Element 379502 ×1
  • Plate Round 2 x 2 with Rounded Bottom [Boat Stud] Light Gray Part 2654 Element 265402 ×1
  • Plate Special 1 x 1 with Clip Light, Bar Hole [Thick Ring] Light Gray Part 4081b Element 408102 ×2
  • Plate Special 1 x 2 with 1 Stud without Groove (Jumper) Light Gray Part 3794a Element 379402 ×1
  • Plate Special 2 x 2 with Pin on Bottom Light Gray Part 2476a Element 4237081 or 4170323 ×1
  • Plate Special 3 x 2 with Rounded End, Hole Light Gray Part 3176 Element 317652 or 317602 ×2
  • Technic Brick 1 x 1 with Pin Hole Light Gray Part 6541 Element 654102 ×2
  • Technic Pin 1/2 without Friction Ridges Light Gray Part 4274 Element 427402 1 spare in the box ×2
  • Tile 2 x 2 with Groove Light Gray Part 3068b Element 306802 ×1
  • Tile Special 1 x 2 Grille with Bottom Groove Light Gray Part 2412b Element 241202 ×1
  • Turntable 2 x 2 Plate - Top Light Gray Part 3679 Element 367952 or 367902 ×1
  • Wedge Plate 3 x 2 Left Light Gray Part 43723 Element 4180542 ×1
  • Wedge Plate 3 x 2 Right Light Gray Part 43722 Element 4180503 ×1
  • Wedge Plate 3 x 4 without Stud Notches Light Gray Part 4859 ×1

Medium Blue 27 pieces

  • Brick 1 x 1 Medium Blue Part 3005 Element 4179830 or 4165452 ×2
  • Brick 1 x 4 Medium Blue Part 3010 Element 4165458 or 4163696 ×2
  • Brick Curved 1 x 2 x 1 1/3 with Curved Top Medium Blue Part 6091 Element 4617019 or 4185668 ×2
  • Brick Curved 2 x 2 x 2/3 Two Studs and Lip End Medium Blue Part 41855 Element 4163719 ×6
  • Brick Sloped 33° 3 x 2 Medium Blue Part 3298 Element 4142994 ×3
  • Brick Wedged, Angled 3 x 2 Left Medium Blue Part 6565 Element 4189122 ×1
  • Brick Wedged, Angled 3 x 2 Right Medium Blue Part 6564 Element 4188785 ×1
  • Mudguard 2 x 4 with 2 x 2 Studs and Flared Wings Medium Blue Part 41854 Element 4162138 ×4
  • Plate Special 2 x 2 with Grills Medium Blue Part 41862 Element 4164348 ×2
  • Tile Special 1 x 2 Grille with Bottom Groove Medium Blue Part 2412b Element 4171075 ×2
  • Wedge Plate 3 x 2 Left Medium Blue Part 43723 Element 4185670 ×1
  • Wedge Plate 3 x 2 Right Medium Blue Part 43722 Element 4185669 ×1

Orange 26 pieces

  • Brick Curved 2 x 2 with Lip, No Studs Orange Part 30602 Element 4169355 ×1
  • Plate 1 x 4 Orange Part 3710 Element 4118782 ×2
  • Plate 2 x 2 Orange Part 3022 Element 4613982 or 4159007 ×4
  • Plate 2 x 3 Orange Part 3021 Element 4125278 ×1
  • Plate Round 1 x 1 with Solid Stud Orange Part 6141 Element 4157103 1 spare in the box ×4
  • Plate Special 1 x 2 Side Handle [Free Ends] Orange Part 2540 Element 4190164 or 4163269 ×4
  • Plate Special 1 x 2 with 1 Stud without Groove (Jumper) Orange Part 3794a Element 4189124 or 4159973 ×2
  • Tile 1 x 2 with Groove Orange Part 3069b Element 4188771 ×4
  • Tile Special 1 x 1 with Clip and Straight Tips Orange Part 2555 Element 4160615 ×2
  • Tile Special 1 x 2 Grille with Bottom Groove Orange Part 2412b Element 4125254 or 3933106 ×2

White 19 pieces

  • Lever Small Base with Black Lever White Part 298c02 Element 73737 ×2
  • Plate 1 x 2 White Part 3023 Element 6552100 or 6548261 ×4
  • Plate 1 x 3 White Part 3623 Element 6552105 or 6550144 ×2
  • Plate 1 x 4 White Part 3710 Element 6552108 or 6548266 ×3
  • Plate 2 x 2 White Part 3022 Element 6552099 or 6548260 ×1
  • Plate 2 x 3 White Part 3021 Element 6550136 or 302101 ×2
  • Plate Round 1 x 1 with Solid Stud White Part 6141 Element 6601919 or 614101 1 spare in the box Also in Trans-Clear ×2
  • Tile Special 1 x 2 Grille with Bottom Groove White Part 2412b Element 6601902 or 241201 ×3

Chrome Silver 4 pieces

  • Antenna 1 x 4 with Rounded Top Chrome Silver Part 3957a Element 4143533 ×2
  • Weapon Harpoon [4 Grooves on Shaft] Chrome Silver Part 57467 ×2

Trans-Clear 3 pieces

  • Brick Sloped 45° 2 x 2 Trans-Clear Part 3039 Element 6514100 or 6244886 ×1
  • Plate Round 1 x 1 with Solid Stud Trans-Clear Part 6141 Element 6514052 or 6240030 1 spare in the box Also in White ×2

Trans-Red 3 pieces

  • Plate Round 1 x 1 with Solid Stud Trans-Red Part 6141 Element 6514051 or 6208450 1 spare in the box ×2
  • Tile Special 1 x 2 Grille with Bottom Groove Trans-Red Part 2412b Element 6250158 or 4190187 ×1

Red 2 pieces

  • Plate 1 x 2 Red Part 3023 Element 302321 ×1
  • Plate Special 1 x 2 Side Handle [Free Ends] Red Part 2540 Element 4140585 or 254021 ×1

Tick each piece as you find it, or mark it missing.

When a piece really is missing

Ask LEGO

LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for the set number and each piece's element ID, the number printed beside the piece in the parts list at the back of the instructions. This checker lists both.

Request a replacement from LEGO

Buy the piece

Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from older or second-hand sets.

Keep a record

Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.