When ordering multiple tanks, please create separate orders for each tank or call us at 858.581.2800 to order, to ensure accurate shipping rates Reliable 63 cubic foot aluminum tank is GREAT for most diving needs. **You can opt to replace this with an upgrade to a converter valve. Capacity (cu in) 552 Water Capacity (lbs) 19.9 Water Capacity (liters) 11.1, 9 Diameter (in) 7.25 Diameter (mm) 184.2 Length (in) 21.7 Length (mm) 551 Cylinder Weight (lbs) 26.9 Cylinder Weight (kgs) 12.2 Buoyancy lbs (full) -2.8 Buoyancy lbs (500 psi) 0.7 Buoyancy lbs (empty) 1.8 Air (cu ft) 63 Air (liters) 1784