Spark-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. Multitank 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.