The Matco Tools 4 and 12 Slot Magnetic Wrench Racks hold wrenches from 10mm to 19mm.Made from non-marring TPR material, the racks are built to be used in all work and storage areas without worry of the holder scratching or denting surfaces. While being ultra-flexible to bend on virtually any ferrous surface, the strong embedded magnets will hold wrenches tight and prevent them from moving around in the tool-box drawer, on the tool cart or even under the hood. The magnetic racks feature a low-profile design, withstand most automotive fluids, and are easy to clean. They also have a modular magnetic design, allowing users to align two or more sets together.