Ingersoll Rand 301B Air Die Grinder Set with Grinding StonesIngersoll Rand Air Die Grinder Set with Grinding Stones As part of an expanded line of long lasting, economical, general purpose grinders, the 301b delivers a number of beneficial features in one compact package. Right angle configuration provides easy access to tight spots, so you can grind, break sharp edges, de burr, port, and polish virtually anywhere! Features include 21,000 RPM 1 4" Collet 1 4" air inlet 0. 25 HP Front Exhaust 24 CFM Kit