Rubber tips protect surfaces and hardware: The rubber tips prevent scratching your key fob hardware, and plastic tip covers on the jaws shield glass from scratches or chips caused by the tool. The comfortable grips and rubber tips help secure the glass, while the curved jaws apply leverage to reduce hand fatigue during scoring. with adjustable pressure: An adjustable set screw lets you control the amount of pressure applied. The set screw is easy to adjust, allowing use on different thicknesses of glass. value and versatility: This tool is suitable for glass fusing, breaking small pieces of glass for crafts, cutting glass for window panes, and most glass projects. It also helps with installing key fob hardware easily. Working performance you can rely on: The running pliers jaws act as a fulcrum, applying pressure evenly on both sides of a score line to run the score through the glass. Running pliers work on straight cuts and also perform well on gentle curves.