Clamping directly to freshly painted or ultra thin-walled frame tubing can cause inadvertent damage. The new ISC-4 securely holds most bikes without clamping on any frame tube. To use, simply insert the ISC-4 into the frame's seat tube, tighten the knob, and clamp into any Park Tool Repair Stand. The ISC-4's hex-shaped shaft resists twisting while clamped in the stand. Works with a huge range of seat tube sizes--anything with an inside diameter of 24mm to 32mm.