Description X-Small Air Pressure Tank 4-3/4L X 1-3/8 Diameter Key Features Constructed of aluminum Overview This is a compact air tank for use with all pneumatic retracts. Air Capacity: 7.05 cu. in. Constructed of aluminum, with a sealed steel cap, this tank is safe for pressures to 150 psi. Approximate Size: 4 3/4 ” L X 1 3/8″ Dia.