Apex scs gama clamp blackstandard compression systemcompression systems are required if you are using threadless forks a threadless headset they replace the 2 lock nuts on standard threaded forks and let you compress and tune your threadless headset this clamp has more clamping power than some of the others on the marketremember when using the apex scs clamp you will have to cut the top of your fork tube down to at least the height of the apex shim to make sure that your clamp fits prope