Storz Fire Hose, also known as supply line hose, large diameter hose (LDH) is used to transport water from a fire hydrant to a fire engine or from one engine to another. Fire apparatus typically carry four and five inch diameter hoses for supply lines and short sections also known as soft suction hose used to move water from a fire hydrant to the fire engine, when the fire apparatus is parked close to the hydrant. The locking storz coupling is sexless, and secures with a 1/4 turn of the coupling.