Park Tool 100-4X Extreme Range Repair Stand Clamp Our most versatile clamp, the 100-4X fits our heavy duty shp stands and works on nearly any bike, no matter what the size or shape of the frame tube. Clamp opens from 7/8 inch to 4-inches (22mm to 100mm). Quick slide lever located next to handle, allowing one-handed tightening. Quick release botton allow head to pivots 90-degrees to clamp either top-and-bottom, or left-and-right sides of tube. Fits any PRS-2, PRS-2OS, PRS-3, PRS-3OS, PRS-4, PRS-4OS, PRS-4W, PRS-11, or PRS-12 Repair Stand