Amazon.com: Goshfun 32Pcs 10-Kinds MOC Pneumatic Parts Bricks with Air Pump Push Rod Switch Piston Air Pipe, DIY Small Particle Stem Building Blocks Toy Set Compatible with Lego, Random Color of Air
BrickLink - Part 4688c01 : LEGO Pneumatic Cylinder with 1 Inlet Medium (48mm) [Pneumatic] - BrickLink Reference Catalog