Designed to protect both the vise jaws and the workpiece from marring and distortion during any clamping applicationCaps are constructed from a hardened aluminum alloy with two built-in circular permanent magnets on the back side which hold the product securely to the viseThe caps are magnetic towards the vise side to prevent steel filings from attaching themselves to the jaws and keep the clamped part from becoming magnetizedAluminum alloy with laminated fiber cover to prevent the absorption of outside materialsHeat parts rapidly by concentrating heat into partUse on workpieces to avoid distortion and clamping marks