Dotco 12-27 Series Heavy Duty Head Right Angle Grinders, 300 Series Collet are designed with ergonomic and durable composite housing. Dotco 12-27 Series Heavy Duty Head Right Angle Grinders, 300 Series Collet are available in front, side, and rear exhaust models. Dotco 12-27 Series Heavy Duty Head Right Angle Grinders, 300 Series Collet feature a robust design that is perfectly suited for industrial applications.