This is the Low Pressure Regulator Hose Available in 32, 36" Features: Low pressure regulator hose, connects first stage to regulator Rubber construction for maximum durability Male end screws in to a first stage low pressure (LP) port Female end screws on to the second stage regulator or octopus The IST LP Rubber Low Pressure Regulator Hose with Screw On Valve Fittings is for divers who insist on the rugged durability found only in rubber. These hoses are virtually indestructible and with proper use and maintenance, can deliver decades of faultless performance. 3/8 inch (9.525 mm) male fitting screws in to a first stage low pressure (LP) port. 9/16 inch (14.29 mm) female fitting screws on to the second stage regulator or octopus."