1. Wide Application Our knife sharpener is not limited only to lawn mower blades. It is also for sharpening the blades of lawn tractors, rototillers, pruners, drill blades and sickle cutters, making it a versatile tool for all your sharpening needs. 2. Effortless to Use Our sharpener is easy to install and use, saving you time and effort. Suitable for drill or hand drill with 1/4' shank. Simply attach it to your drill and you can sharpen your blades in no time. This is a tool to quickly improve the efficiency of your dull blades and increase your productivity. 3. Effective Blade Balancing Thanks to the compatibility with Model 42100, the included blade balancer ensures balance for your lawnmower. The balancer features multiple diameter levels on the knife holder, allowing you to test and balance according to your blade's diameter for precise and effective results. 4. Durable Quality Our lawn mower knife sharpener is crafted from robust corundum, built to withstand the test of time. This quality product is designed for longevity, promising years of reliable service in garden maintenance while delivering exceptional value for money.