Review on 🔧 EKWB EK-Quantum Torque STC-10/16 Compression Fitting for Soft Tubing, 10/16mm (3/8 inch Inner Diameter, 5/8 inch Outer Diameter), Black - Pack of 6 by Nate Skinner

This fitting is for 5/8 OD You can check the OD to ensure your block has enough room for 5/8 OD. The hole for connecting the GTX 680 water block is too close to the GPU card. I couldn't tighten g 1/4 because the edge of the GTX 680 card is in the way. I don't want to use a drill to cut the GPU board. I end up switching both connection holes down where there are no obstructions. The caveat is that if the two holes are on the same side, you may need to make sure that routing the pipe doesn't cause problems. In my case, I have a problem manually tightening one of the connections.