Ideal for easy separation of quick disconnect style fittings making fuel filter replacement fast and simple. Coupler fittings feature a locking mechanism inside the outer housing that goes over the lip of the fuel filter while the tool gets under the locking mechanism and releases the inner lip. Designed for 5/16 and 3/8 fuel lines on 1989 and newer vehicles. This tool is necessary for fuel, heater and A/C line service on many late model vehicles. All-metal construction for durability, strength and longevity. Easy to grasp design for strong grip and maximum torque. Easy to Use: Release the fuel line locking mechanism by listening for the slight “clickinwhich means the tool has done its job allowing you to pull off the filter easily.