12R9180-48 Dotco 12R91 Series Precision Grinder. Dotco 12R91 Series Precision Grinders requires no air line lubrication. Dotco 12R91 Series Precision Grinders feature high precision ball bearings for long life expectancy and maximizes productivity with a two-stage turbine motor. Dotco 12R91 Series Precision Grinders can achieve a superb finish with its high speed and precision spindle. Dotco 12R91 Series Precision Grinders are light weight and have a durable aluminum housing. Dotco 12R91 Series Precision Grinders feature low vibration and quiet operation that minimizes operator fatigue. Collet Size: 1/8” Free Speed (rpm): 65,000 Overhose: 4ft/1.2m Abrasive Capacity: 1/8” Carbide Burr, 3/8” Diamond Pin Type Housing: Composite Weight: 0.4lbs/0.18kg Overall Length: 5.8”/147mm Air Inlet Size: 1/8”