BrickLink - Part 21828c01 : LEGO Pneumatic Cylinder V2 1 x 11 [Pneumatic] - BrickLink Reference Catalog
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