Dotco 12LF Series Right Angle Grinders, 300 Series Collet feature ergonomic and durable composite housing. Dotco 12LF Series Right Angle Grinders, 300 Series Collet are available in front and rear exhaust models. Dotco 12LF Series Right Angle Grinders, 300 Series Collet feature an ergonomic and balanced design that minimizes operator fatigue.