Review on Oetiker Stepless Clamps Single Available Tools & Equipment by Joel Wright

These are high-quality oetiker clamps. They didn't work for my application, but that's not the fault of the clamps. 9/16 inch is the inside diameter of the clamp when fully open. I bought these to use with a 9/16" OD x 5/16" ID gas hose. They fit perfectly over the hose. It turned out that the splines I bought were a bit oversized at 3/8", so that after clamping, the outside diameter in the area to be clamped was actually 5/8", i.e. too small. Keep in mind if you're trying to use this in a keg beer setup where vendors usually offer larger spikes these clamps probably won't work for you, go for a slightly larger size. If your notches are 5/16 inch this should work.