Make sure your next dive is a safe one with this great emergency tank. **You can opt to replace this with an upgrade to a converter valve. Capacity (cu in) 263 Water Capacity (lbs) 9.5 Water Capacity (liters) 4.3 Diameter (in) 5.25 Diameter (mm) 133.4 Length (in) 19.9 Length (mm) 505 Cylinder Weight (lbs) 13.6 Cylinder Weight (kgs) 6.2 Service Pressure (psi) 3000 Service Pressure (bar) 207 Buoyancy lbs (full) -2.4 Buoyancy lbs (500 psi) -0.7 Buoyancy lbs (empty) -0.2 Air (cu ft) 30 Air (liters) 850