M18™ is the world's first battery platform to offer a complete range of grinders, from 4-1/2" to 9" all on the same battery. M18 FUEL™ is engineered for the most demanding tradesmen in the world. Delivering unrivaled performance in a compact structure, all M18 FUEL™ products feature three MILWAUKEE® exclusive innovations -- The POWERSTATE™ Brusless Motor, REDLITHIUM™ Battery Pack and REDLINK PLUS™ Intelligence Hardware and Software -- that deliver unmatched power, run-time and durability. Simply put, The MILWAUKEE® M18 FUEL™ line of cordless grinders deliver the best combination of power and run-time, all on the M18™ REDLITHIUM™ battery platform.