Lego? Parts: Technic, Gear Rack 1 x 4 (Black) by Parts/Elements - Technic, Gears, Storage & Accessories - Amazon Canada
Amazon.com: PHYNEDI Basic Rack Pinion Parts Bricks Compatible with Lego Technic, DIY Small Particle Stem Building Blocks Educational Construction Toy Set, Random Color (545 Pieces) : Toys & Games
LEGO Technic - Short Framed Steering Rack Set with Wheels support - new parts | eBay
FLLCasts | Rack attachment for lifting built with LEGO Mindstorms EV3
5 Lego Technic Gear Rack Alternatives - YouTube
laser cut LEGO rack and pinion : r/mechanical_gifs