Cylinder TrucksSpark-resistant Aluminum Cylinder Trucks for safe, efficient handling of pressurized tanks. Choose the heavy-duty single frame for cylinders 9″ in diameter or the multi-tank frame that fits over the regular box frame for use with most standard size cylinders. Balanced frames roll easily on 12″ x 31⁄2″, fully-pneumatic tires and feature hand brakes for added safety. A multi-tank frame is available with and without brakes. 1″ steel axle is enclosed in protective housing with sealed bearings. Trucks are constructed of 15⁄16″ O.D. aluminum tubing with notched joints and solid welds.