Zip-Rip is a simple tool that clamps on to any standard tape measure and secures a razor knife to the end hook. With Zip-Rip you no longer need to use bulky t-squares or messy chalk lines. You get square cuts and straight rips every time. Simply hold the tape, at the required measurement against the drywall board. While gripping the Zip-rip with the other hand just slide down the board for straight rips or square cuts each and every time. Zip-Rip also holds a pencil securely so you can mark electric boxes and outlets for fast and easy cutouts. The pencil holder is great for scribing irregular shapes, allowing for tight fitting pieces, and also works as a radius marking tool.