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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.

Level Four - Kit 12, Inventor's Lab

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20211 Level Four - Kit 12, Inventor's Lab

203 pieces in 62 part and color combinations, plus 1 minifigure.

The piece count includes the 5 parts inside the set's minifigures, which this inventory lists separately. Spare parts are counted in neither figure.

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.

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Piece checklist

Tan 88 pieces

  • Brick 1 x 1 Tan Part 3005 Element 4113915 or 300505 ×4
  • Brick 1 x 2 Tan Part 3004 Element 4109995 or 300405 ×3
  • Brick 1 x 3 Tan Part 3622 Element 4162465 or 4113920 ×2
  • Brick 1 x 6 Tan Part 3009 Element 4112982 or 300905 ×2
  • Brick Curved Inverted 6 x 1 Tan Part 42023 Element 6495042 or 6030729 ×12
  • Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope) Tan Part 54200 Element 4516055 or 4278069 ×3
  • Brick Sloped 45° 2 x 1 with Bottom Pin Tan Part 3040b Element 4121972 or 4113989 ×2
  • Brick Sloped 45° 2 x 2 Tan Part 3039 Element 4114322 ×8
  • Brick Sloped 75° 2 x 1 x 3 with Hollow Stud Tan Part 4460b Element 4129996 ×1
  • Brick Sloped Inverted 45° 2 x 1 Tan Part 3665 Element 4159196 or 366505 ×10
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] Tan Part 3660 Element 4118866 ×2
  • Brick Sloped Inverted 75° 2 x 1 x 3 Tan Part 2449 Element 6030731 or 4616212 ×2
  • Plate 1 x 1 Tan Part 3024 Element 4159553 or 302405 ×3
  • Plate 1 x 2 Tan Part 3023 Element 4113917 or 302305 ×4
  • Plate 1 x 3 Tan Part 3623 Element 4121921 or 362305 ×3
  • Plate 1 x 6 Tan Part 3666 Element 4124067 or 366605 ×2
  • Plate 1 x 8 Tan Part 3460 Element 4114324 or 346005 ×2
  • Plate 2 x 2 Corner Tan Part 2420 Element 4114077 or 242005 ×6
  • Plate 2 x 4 Tan Part 3020 Element 4114309 or 302005 ×1
  • Plate 2 x 6 Tan Part 3795 Element 4113993 or 379505 ×2
  • Plate 4 x 6 Tan Part 3032 Element 4114001 ×3
  • Plate 4 x 8 Tan Part 3035 Element 4509897 or 4191103 ×2
  • Plate Special 1 x 2 with 1 Stud with Groove (Jumper) Tan Part 3794b Element 4155708 ×4
  • Technic Gear 12 Tooth Bevel Tan Part 6589 Element 4565452 or 4514556 ×5

Black 53 pieces

  • Brick Sloped 45° 2 x 1 with Bottom Pin Black Part 3040b Element 4121966 or 304026 ×4
  • Brick Special 1 x 1 with Handle Black Part 2921 Element 6170566 or 292126 ×2
  • Brick Special 1 x 2 with Vertical Clip [Open O Clip] Black Part 30237b Element 6330197 or 6092876 ×2
  • Dish 2 x 2 Inverted [Radar] Black Part 4740 Element 474026 ×1
  • Plate Round 1 x 1 with Solid Stud Black Part 6141 Element 614126 ×9
  • Plate Special 1 x 2 Side Handle [Free Ends] Black Part 2540 Element 4140588 or 254026 ×12
  • Tap 1 x 1 without Hole in Spout Black Part 4599b Element 459926 ×1
  • Technic Axle 4 Black Part 3705 Element 370526 ×2
  • Technic Axle 6 Black Part 3706 Element 370626 ×2
  • Technic Axle Connector Smooth [with x Hole + Orientation] Black Part 59443 Element 6084612 or 4512363 ×2
  • Technic Beam 1 x 2 Thick with Pin Hole and Axle Hole Black Part 60483 Element 6265091 or 6006140 ×1
  • Technic Beam 1 x 5 Thick Black Part 32316 Element 4142135 or 4140429 ×2
  • Technic Brick 1 x 6 [5 Pin Holes] Black Part 3894 Element 389426 ×4
  • Technic Gear 12 Tooth Double Bevel Black Part 32270 Element 4177431 ×2
  • Technic Gear 36 Tooth Double Bevel Black Part 32498 Element 4255563 or 4177434 ×2
  • Technic Plate 1 x 5 with Smooth Ends, 4 Studs and Centre Axle Hole Black Part 32124 Element 6280168 or 4114689 ×1
  • Technic Plate Rotor 6 Blade with Clip Ends Connected [aka Water Wheel] - Hollow Studs Black Part 64566 Element 4539442 ×2
  • Tile Special 1 x 1 with Clip with Rounded Tips Black Part 12825 Element 6030718 ×2

Dark Blue 19 pieces

  • Brick 1 x 2 Dark Blue Part 3004 Element 4249891 ×3
  • Tile 1 x 2 with Groove Dark Blue Part 3069b Element 6554190 or 4528488 ×16

Light Bluish Gray 14 pieces

  • Brick Sloped 33° 3 x 2 Light Bluish Gray Part 3298 Element 4211421 ×1
  • Equipment Signal Paddle Light Bluish Gray Part 3900 Element 4211753 ×1
  • Plate Round 2 x 2 with Rounded Bottom [Boat Stud] Light Bluish Gray Part 2654 Element 4278273 or 4276273 ×6
  • Technic Axle 3 Light Bluish Gray Part 4519 Element 4211815 ×1
  • Technic Bush Light Bluish Gray Part 3713 Element 6275844 or 6271817 ×2
  • Technic Pin without Friction Ridges Lengthwise Light Bluish Gray Part 3673 Element 4211807 or 3673194 ×1
  • Technic Plate 2 x 6 [5 Holes] Light Bluish Gray Part 32001 Element 4211542 ×2

Dark Bluish Gray 13 pieces

  • Brick Special 1 x 2 with Pin Dark Bluish Gray Part 2458 Element 4211087 ×4
  • Plate 1 x 4 Dark Bluish Gray Part 3710 Element 4211001 ×2
  • Technic Axle 4 with Stop Dark Bluish Gray Part 87083 Element 6083620 or 4560177 ×2
  • Technic Plate 2 x 4 [3 Holes] Dark Bluish Gray Part 3709 Element 4227398 ×2
  • Tile 1 x 6 with Groove Dark Bluish Gray Part 6636 Element 4210651 ×3

Dark Red 10 pieces

  • Plate 1 x 2 Dark Red Part 3023 Element 4539097 or 4162582 ×7
  • Tile 1 x 1 with Groove Dark Red Part 3070b Element 4550169 or 4187196 ×1
  • Tile 1 x 4 with Groove Dark Red Part 2431 Element 4539060 or 4164220 ×2

White 4 pieces

  • Brick Special 1 x 1 Studs on 4 Sides White Part 4733 Element 4111971 or 473301 ×1
  • Technic Brick 1 x 2 [1 Pin Hole] White Part 3700 Element 6619284 or 370001 ×3

Trans-Clear 2 pieces

  • Tile Round 1 x 1 Trans-Clear Part 98138 Element 6514191 or 6274738 ×2

Minifigures 1 figure

  • MBA Level Four Kit 12 Minifigure, checked as a whole figure ×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.

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