This 5" finishing sander with 8 mm orbit is constructed of precision molded composites for strength and durability, while reducing operator fatigue. This construction also reduces sound for increased comfort. True 12,000 rpm performance for maximum productivity. Counter-balanced for specific size backup pad. Features moisture-resistant composite rotors and premium counterweight bearings for long life and superior reliability. MR-Series sanders can be converted to vacuum operation with the addition of an external or self-generating vacuum adapter.