The Scotty 4577 Fire Coupler Spanner and Gas Wrench is a durable, light weight wrench used to tighten and loosen 1" (25mm), 1-1/2" (38mm), 1-3/4" (44mm), 2" (51mm) 2-1/2" (65mm) and 3" (76mm) fire hose line couplers, swivel hose fittings and anvil lug couplers. The tool can also be used to open standard, 70mm caps on foam concentrate containers.