This closed hi-hat attachment utilizes a specially designed screw clutch, allowing for quick, easy, and precise adjustments. The space between the hi-hat cymbals can be adjusted by rotating the screw clutch clockwise or counterclockwise. The top cymbal is supported by a center spring, allowing for the hi-hat cymbals to be placed in the open position. This clamp can be attached to an existing stand pipe that is 15.9mm to 28.9mm in diameter. If your kit requires a lot of clamps, set up will be a lot faster and easier with attachments that feature the FastClamp Easy Set-Up System.