BlockTalk Find Your Set

Free tool

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.

Sea Jet

Checking

5521 Sea Jet

401 pieces in 147 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.

Show

Piece checklist

Plates 152 pieces

  • Plate 1 x 1 Black Part 3024 Element 302426 ×2
  • Plate 1 x 10 Black Part 4477 Element 447726 ×2
  • Plate 1 x 2 Black Part 3023 Element 302326 ×2
  • Plate 1 x 6 Black Part 3666 Element 366626 ×3
  • Plate 1 x 8 Black Part 3460 Element 346026 ×1
  • Plate 2 x 2 Black Part 3022 Element 302226 ×2
  • Plate 2 x 3 Black Part 3021 Element 302126 ×6
  • Plate 2 x 4 Black Part 3020 Element 302026 ×1
  • Plate 2 x 6 Black Part 3795 Element 379526 ×1
  • Plate 2 x 8 Black Part 3034 Element 303426 ×2
  • Plate 1 x 1 Blue Part 3024 Element 302423 ×6
  • Plate 1 x 2 Blue Part 3023 Element 302323 ×2
  • Plate 1 x 3 Blue Part 3623 Element 362323 ×4
  • Plate 1 x 4 Blue Part 3710 Element 371023 ×2
  • Plate 2 x 2 Corner Blue Part 2420 Element 242073 or 242023 ×2
  • Plate 2 x 3 Blue Part 3021 Element 302123 ×2
  • Plate 2 x 4 Blue Part 3020 Element 4240375 or 302023 ×2
  • Plate 1 x 2 Light Gray Part 3023 Element 302302 ×2
  • Plate 1 x 3 Light Gray Part 3623 Element 362302 ×1
  • Plate 1 x 4 Light Gray Part 3710 Element 371002 ×2
  • Plate 1 x 6 Light Gray Part 3666 Element 366602 ×2
  • Plate 1 x 8 Light Gray Part 3460 Element 346002 ×1
  • Plate 2 x 2 Light Gray Part 3022 Element 302202 ×2
  • Plate 2 x 3 Light Gray Part 3021 Element 302102 ×1
  • Plate 2 x 8 Light Gray Part 3034 Element 303402 ×1
  • Plate 6 x 14 Light Gray Part 3456 Element 345602 ×1
  • Plate 1 x 1 Red Part 3024 Element 302421 ×6
  • Plate 1 x 2 Red Part 3023 Element 302321 ×12
  • Plate 1 x 3 Red Part 3623 Element 362321 ×6
  • Plate 1 x 4 Red Part 3710 Element 371021 ×4
  • Plate 1 x 6 Red Part 3666 Element 366621 ×4
  • Plate 2 x 2 Red Part 3022 Element 4613974 or 302221 ×3
  • Plate 2 x 2 Corner Red Part 2420 Element 242071 or 242021 ×4
  • Plate 2 x 3 Red Part 3021 Element 302121 ×7
  • Plate 2 x 4 Red Part 3020 Element 302021 ×4
  • Plate 4 x 4 Red Part 3031 Element 4243814 or 303121 ×2
  • Plate 1 x 1 White Part 3024 Element 6548262 or 302401 ×6
  • Plate 1 x 2 White Part 3023 Element 6552100 or 6548261 ×7
  • Plate 1 x 3 White Part 3623 Element 6552105 or 6550144 ×4
  • Plate 1 x 4 White Part 3710 Element 6552108 or 6548266 ×4
  • Plate 1 x 6 White Part 3666 Element 6552107 or 6548265 ×2
  • Plate 2 x 10 White Part 3832 Element 6552109 or 383201 ×2
  • Plate 2 x 2 White Part 3022 Element 6552099 or 6548260 ×3
  • Plate 2 x 2 Corner White Part 2420 Element 6548254 or 242051 ×2
  • Plate 2 x 3 White Part 3021 Element 6550136 or 302101 ×8
  • Plate 2 x 6 White Part 3795 Element 6550146 or 379501 ×5
  • Plate 2 x 3 Yellow Part 3021 Element 302124 ×1
  • Plate 2 x 4 Yellow Part 3020 Element 302024 ×1

Bricks Sloped 42 pieces

  • Brick Sloped 45° 2 x 1 with Bottom pin, with 9 Large + 3 Small White Buttons Print Black Part 3040bpr0011 Element 4251811 or 4121975 ×2
  • Brick Sloped 45° 2 x 2 with 3 Gauges and 3 Knobs Print Black Part 3039pr9970 Element 4251812 or 4163777 ×1
  • Brick Sloped 33° 3 x 1 Red Part 4286 Element 428621 ×2
  • Brick Sloped 45° 2 x 1 with Bottom Pin Red Part 3040b Element 4121934 or 304021 ×2
  • Brick Sloped 45° 2 x 2 Double Convex Red Part 3045 Element 4163087 or 304521 ×2
  • Brick Sloped 45° 2 x 3 Red Part 3038 Element 6303213 or 4195081 ×2
  • Brick Sloped 45° 2 x 4 Red Part 3037 Element 303721 ×2
  • Brick Sloped 75° 2 x 2 x 3 Double Convex Red Part 3685 Element 4588468 or 4280140 ×2
  • Brick Sloped Inverted 34° 3 x 1 without Internal Stopper Red Part 4287a ×2
  • Brick Sloped Inverted 45° 2 x 1 Red Part 3665 Element 366521 ×4
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] Red Part 3660 Element 366021 ×2
  • Brick Sloped Inverted 45° 3 x 1 Double with 2 Completely Open Studs Red Part 2341 Element 4161065 or 234121 ×2
  • Brick Sloped Inverted 45° 4 x 4 Double with 4 x 2 Recessed Red Part 4854 Element 4643320 or 4603489 ×6
  • Brick Sloped 10° 6 x 8 White Part 4515 Element 6441085 or 4529681 ×1
  • Brick Sloped 33° 3 x 1 White Part 4286 Element 6632142 or 428601 ×2
  • Brick Sloped 45° 2 x 1 with Bottom Pin White Part 3040b Element 6552115 or 4121932 ×2
  • Brick Sloped 45° 2 x 4 White Part 3037 Element 6552102 or 303701 ×2
  • Brick Sloped 45° 2 x 8 White Part 4445 Element 4163984 ×2
  • Brick Sloped 75° 2 x 1 x 3 with Open Stud White Part 4460a ×2

Bricks 36 pieces

  • Brick 1 x 1 Black Part 3005 Element 300526 ×2
  • Brick 1 x 2 Black Part 3004 Element 300426 ×6
  • Brick 1 x 3 Black Part 3622 Element 362226 ×2
  • Brick 1 x 3 Blue Part 3622 Element 362223 ×4
  • Brick 1 x 2 Light Gray Part 3004 Element 300402 ×4
  • Brick 1 x 4 Light Gray Part 3010 Element 301002 ×2
  • Brick 2 x 2 Light Gray Part 3003 Element 4103591 or 300352 ×1
  • Brick 2 x 2 Corner Light Gray Part 2357 Element 235752 or 235702 ×2
  • Brick 1 x 1 Red Part 3005 Element 300521 ×4
  • Brick 1 x 2 Red Part 3004 Element 4613961 or 300421 ×2
  • Brick 1 x 3 Red Part 3622 Element 362221 ×2
  • Brick 1 x 6 Red Part 3009 Element 300921 ×1
  • Brick 2 x 3 Red Part 3002 Element 300271 or 300221 ×2
  • Brick 2 x 4 Red Part 3001 Element 300121 ×2

Tiles 31 pieces

  • Tile 1 x 2 with Groove Black Part 3069b Element 306926 ×2
  • Tile 1 x 4 with Groove Light Gray Part 2431 Element 243102 ×1
  • Tile 1 x 1 with Groove Red Part 3070b Element 307021 ×2
  • Tile 2 x 2 with Groove Red Part 3068b Element 306821 ×2
  • Tile 1 x 1 with Groove White Part 3070b Element 6550138 or 307001 ×4
  • Tile 1 x 2 with Groove White Part 3069b Element 6548264 or 306901 ×14
  • Tile 1 x 4 with Groove White Part 2431 Element 6548255 or 243101 ×2
  • Tile 1 x 8 with Groove White Part 4162 Element 6552110 or 416201 ×2
  • Tile 1 x 2 with Groove Yellow Part 3069b Element 306924 ×2

Plates Special 28 pieces

  • 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 Horizontal [Thick U Clip] Blue Part 6019 Element 601973 or 601923 ×4
  • Plate Special 1 x 2 with Bar Up [Horizontal Arm 6mm] Light Gray Part 4623 Element 462302 ×2
  • Plate Special 1 x 2 with Ladder Light Gray Part 4175 Element 4100526 or 417502 ×2
  • Plate Special 1 x 1 with Clip Light, Bar Hole [Thick Ring] Red Part 4081b Element 6281994 or 4632572 ×6
  • Plate Special 1 x 2 Side Handle [Free Ends] Red Part 2540 Element 4140585 or 254021 ×2
  • Plate Special 1 x 1 with Clip Vertical [Thick U Clip] White Part 4085c Element 408501 ×4
  • Plate Special 1 x 2 Side Handle [Free Ends] White Part 2540 Element 4140583 or 254051 ×3
  • Plate Special 1 x 1 with Clip Light, Bar Hole [Thick Ring] Yellow Part 4081b Element 6281992 or 4632569 ×2
  • Plate Special 1 x 2 Side Handle [Free Ends] Yellow Part 2540 Element 4140587 or 254024 ×1

Plates Round Curved and Dishes 16 pieces

  • Plate Round 1 x 1 with Solid Stud Black Part 6141 Element 614126 ×2
  • Plate Round 1 x 1 with Solid Stud Light Gray Part 6141 Element 614102 ×6
  • Plate Round 2 x 2 with Rounded Bottom [Boat Stud] Light Gray Part 2654 Element 265402 ×4
  • Plate Round 1 x 1 with Solid Stud Red Part 6141 Element 614121 ×4

Hinges, Arms and Turntables 14 pieces

  • Hinge Brick 1 x 2 Base Black Part 3937 Element 393726 ×2
  • Hinge Brick 1 x 2 Top Plate Thin Black Part 3938 Element 393826 ×2
  • Hinge Plate 1 x 2 with 2 Fingers and Hollow Studs Black Part 4276b Element 4264363 or 4256402 ×2
  • Hinge Plate 1 x 2 with 3 Fingers [Hollow Studs] Black Part 4275b Element 427526 ×2
  • Hinge Brick 1 x 2 Base White Part 3937 Element 6619287 or 393701 ×2
  • Hinge Brick 1 x 2 Top Plate Thin White Part 3938 Element 393801 ×2
  • Hinge Tile 1 x 4 White Part 4625 Element 4264365 or 4258048 ×1
  • Hinge Vehicle Roof 4 x 4 Sunroof with Ledges White Part 2349b Element 4177755 or 234901 ×1

Bricks Curved 12 pieces

  • Brick Curved 1 x 2 x 1 1/3 with Curved Top Blue Part 6091 Element 6347945 or 4519981 ×2
  • Brick Curved 1 x 2 x 1 1/3 with Curved Top Red Part 6091 Element 6184782 or 609121 ×2
  • Brick Curved 1 x 2 x 1 1/3 with Curved Top White Part 6091 Element 6285777 or 609101 ×6
  • Brick Curved 2 x 4 x 1 1/3 White Part 6081 Element 608151 or 608101 ×2

Plates Wedged 12 pieces

  • Wedge Plate 3 x 4 without Stud Notches Blue Part 4859 ×2
  • Wedge Plate 8 x 8 with 3 x 4 Cutout Blue Part 6104 Element 610423 ×1
  • Wedge Plate 3 x 4 without Stud Notches Red Part 4859 ×2
  • Wedge Plate 3 x 4 without Stud Notches White Part 4859 Element 4215973 or 4199395 ×4
  • Wedge Plate 3 x 6 Cut Corners White Part 2419 Element 6552090 or 241901 ×1
  • Wedge Plate 8 x 8 with 3 x 4 Cutout White Part 6104 ×2

Technic Bricks 10 pieces

  • Technic Brick 1 x 2 [1 Pin Hole] Black Part 3700 Element 370026 ×2
  • Technic Brick 1 x 2 [1 Pin Hole] Light Gray Part 3700 Element 370002 ×4
  • Technic Brick 1 x 1 with Pin Hole White Part 6541 Element 6609542 or 654101 ×4

Technic Pins 8 pieces

  • Technic Pin with Friction Ridges Lengthwise and Center Slots Black Part 2780 Element 4121715 or 278026 ×4
  • Technic Axle Pin without Friction Ridges Lengthwise Light Gray Part 3749 Element 4184168 or 4154179 ×2
  • Technic Pin without Friction Ridges Lengthwise Light Gray Part 3673 Element 4184166 or 367302 ×2

Technic Connectors 6 pieces

  • Technic Axle and Pin Connector Light Gray Part 3651 Element 4105243 or 365102 ×2
  • Technic Axle and Pin Connector Toggle Joint Toothed [with Slots] Light Gray Part 4273b Element 427302 ×4

Bars, Ladders and Fences 4 pieces

  • Antenna 8H Whip Light Gray Part 2569 Element 4188299 or 256902 ×2
  • Lever Small Base with Light Gray Lever Light Gray Part 298c03 Element 73777 ×2

Bricks Special 4 pieces

  • Brick Special 1 x 1 with Headlight Light Gray Part 4070 Element 407002 ×2
  • Brick Special 2 x 2 with Pin and No Axle Hole Light Gray Part 4730 Element 473002 ×2

Technic Bushes 4 pieces

  • Technic Bush Light Gray Part 3713 Element 4125313 or 659002 ×4

Bricks Wedged 3 pieces

  • Brick Wedged, Sloped Inverted 4 x 4 Triple [2 Connections between Front Studs] Red Part 4855 Element 6021528 or 4258397 ×2
  • Brick Wedged, Sloped Inverted 6 x 4 with 2 Stud Connections White Part 4856a ×1

Tiles Special 3 pieces

  • Tile Special 1 x 2 Grille with Bottom Groove Light Gray Part 2412b Element 241202 ×3

Minifig Accessories 2 pieces

  • Equipment Cup / Mug [Plain] Yellow Part 3899 Element 389924 ×2

Minifig Shields, Weapons, & Tools 2 pieces

  • Weapon Lance Light Gray Part 3849 Element 4213223 or 4189054 ×2

Panels 2 pieces

  • Panel 1 x 2 x 1 [Square Corners] White Part 4865a Element 486501 ×2

Technic Axles 2 pieces

  • Technic Axle 4 Black Part 3705 Element 370526 ×2

Technic Steering, Suspension and Engine 2 pieces

  • Technic Steering Wheel Small (3 Studs Diameter) Light Gray Part 2819 Element 4113032 or 281902 ×2

Transportation - Sea and Air 2 pieces

  • Propeller 3 Blade 3 Diameter with Axle Cross Black Part 6041 Element 604126 ×2

Windscreens and Fuselage 2 pieces

  • Windscreen 3 x 4 x 1 1/3 with 2 Studs on Top Trans-Light Blue Part 2437 Element 6507914 or 6253361 ×2

Stickers 1 piece

  • Sticker Sheet for Set 5521-1 [No Color/Any Color] Part 821472 ×1

Windows and Doors 1 piece

  • Glass 2 x 3 for Hinge Car Roof 4 x 4 Sunroof with Ridges Trans-Light Blue Part 2348b Element 234842 ×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.

We value your privacy

We use cookies 🍪 for analytics and to improve your experience. Read our privacy policy