Make sure your next dive is a safe one with this great emergency tank. comes with k-Valve. Capacity (cu in) 166 Water Capacity (lbs) 6 Water Capacity (liters) 2.7 Diameter (in) 4.38 Diameter (mm) 111.3 Length (in) 17.7 Length (mm) 450 Cylinder Weight (lbs) 7.8 Cylinder Weight (kgs) 3.5 Service Pressure (psi) 3000 Service Pressure (bar) 207 Buoyancy lbs (full) -1.5 Buoyancy lbs (500 psi) -0.4 Buoyancy lbs (empty) -0.2 Air (cu ft) 19 Air (liters) 538