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 containersand comes in a Hi-Viz yellow.