Great size for primary youth cylinder or instructional pool cylinder, Catalina 63 Cubic Ft. (9 liter) Aluminum Tank with Pro Valve. Cylinder comes with a K Pro Valve, which is one of the highest flow cylinder valves available today and is also a convertible valve. Whether you dive Yoke or DIN regulators this valve will work for both. Valve has easily removed 200 bar DIN insert to convert the valve for use with DIN regulators. Valve has a heavy duty deign with a smooth operating mechanism and multi-ported burst disc plug for added safety. The K Pro Valve is nitrox compatible up to 40%. Aluminum cylinders unlike steel cylinders don't rust, they oxidize. The oxidization of aluminum forms a protective coat that hinders the continuation of corrosion making aluminum cylinders less likely to be condemned due to excessive corrosion. When shipped the tanks valves will be removed and the tank will require re-inspection before being filled. Note: All Catalina cylinders are nitrox ready and meet certificated specifications of the US Department of Transportation (DOT) with DOT-3AL specification and Transport Canada Safety and Security (TC) with TC-3ALM specifications. Purchasers should check with other country requirements to know if the cylinders are certified for use in that country. The 63 cubic foot (9 liter) cylinder is a 3000 psi (207 bar) rated tank that measures 21.7" (55 cm) in height with a 7.25" (18.4 cm) diameter. The tank weighs 26.9 lbs. (12.2 kg) and is negatively buoyant 2.8 lbs. (1.27 kg) when full and positively buoyant 0.7 lbs. (317.5 g) when at 500 psi (50 bars).