The worlds first cordless grinder delivers the power of a corded grinder with upto 5X more runtime and upto 10X longer motor life. The M18™ FUEL™ 4-1/2 in/5 in grinder supplies maximum sustained power to complete the toughest grinding, surface preparation and cutting applications. The POWERSTATE™ brushless motor provides upto 10X longer motor life and lower cost of ownership. The M18™ REDLITHIUM™ HIGH DEMAND™ 9 Battery pack delivers upto 5X more runtime, 35% more power and runs 60% cooler than standard 18 V Lithium-Ion batteries. It maintains full power and runs substantially cooler through heavy applications, allowing users to push their cordless tools harder and longer than ever before. The M18™ REDLITHIUM™ HIGH DEMAND™ 9 Battery is fully compatible with 100 plus M18™ tools. The grinder features REDLINK™ Plus™ intelligence, the most advanced system of cordless power tool electronics, for maximum performance. A rapid stop brake feature stops accessories in under 2 s. The 18 V Lithium-Ion grinder's thin body design gives it optimized balance to rest easily in your hands. Tool-free accessory changes using the FIXTEC nut and guard adjustments mean less downtime during work. The grinder is built with the same tool body, gearing system and anti-vibration side-handle as Milwaukee® 's legendary high performance corded grinders for maximum durability on the job.