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.
Large Figure Spinner / Propeller with Code Print (Rhotuka)Pearl Light GrayPart 50899pr0002Element 4272617 or 4256099×1
Large Figure Spinner / Propeller without Code (Rhotuka) [Plain]Pearl Light GrayPart 50899Element 4247657×1
Large Figure Spinner Rod 2.5L with Gear 8 Tooth (Rhotuka)YellowPart 50903Element 4263698×1
Technic Special
2 pieces
Technic Tooth 1 x 3 with Axle Hole [Rounded Underside]Trans-GreenPart 41669Element 4163576×2
String, Bands and Reels
1 piece
Rubber Band 15mm [Square Cross Section]YellowPart 23229Element 4125669 or 41243351 spare in the box×1
Technic Beams Special
1 piece
Technic Beam Special 8 x 3 x 2 (Visorak Torso)Light Bluish GrayPart 50904Element 4252399×1
Tools
1 piece
Rip Cord, Rhotuka, 12L with Connector Block 1 x 3 x 5BlackPart 50900Element 4252442×1
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.
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.