Dual Shut-Off. 1/4" (6.35mm) inside diameter. Connecting and disconnecting your fuel line in a split second. Press the thumb latch and the coupling halves disconnect. The half with the thumb latch is equipped with an automatic fuel shut-off, the other half will stay open. Use dual shut-off for tanks with a crossover line. To connect the fuel lines, just press the coupling halves together. Comes with Viton O-rings. Can be used with any type of pump gas or racing fuels. Note: See 960475 for replacement 1/4" O-ring