LEGO Technic Pneumatics - hose connector with axle connection
Lego Pneumatic Hoses
Lego compatible pneumatic tube
Amazon.com: Build 19 Piece Pneumatic Kits with Technik Parts Contains Air Pump, Piston Pressure Rod, Cylinder,Pneumatic Hose &More,Great for DIY, MOC Tech, Compatible with Lego : Industrial & Scientific
Amazon.com: LEGO Technic 4 pcs NEW YELLOW MINI PNEUMATIC PISTON CYLINDERS Air pressure Pump pack lot set switch hose small little robot robotics : Toys & Games