0.3 HP Motor Output More powerful than pneumatic 0.25 HP die grinders Max RPM = 20,000 1/4" Collet, 1/8" compatible Rated for 2" Size accessories Optimized RPM setting for most common accessories Dial in the right Max RPM for safer operation Mode 1=10,000, Mode 2=15,000, Mode 3=20,000 Saves Time.