Use with 51151 Backing Pad (not included), 180 mm (7") diameter, with mounting hardware. Accepts optional 180 mm (7") diameter Abrasive Discs with 22 mm (7/8") center hole. Dynabrade's 1.3 hp (970 W) Right Angle Sander offer countless grinding and material removal solutions to industries such as metal/stainless steel fabrication, composites, masonry, ironwork and general welding. Designed to the Dynabrade standard of excellence, these tools offer a wide array of features to increase efficiency and maximize operator comfort!Vibration Dampening Side Handle Specially designed to reduce vibration transfer to operator. Removable for left or right hand use. Rotational Exhaust System Rotates a full 360 degree to ensure that exhaust is directed away from operator. Cast Aluminum Construction Tool housing and handle made of solid cast aluminum. Safety-Lock Throttle Lever Prevents accidental start-up of tool. Lever has no sharp edges or pinch-points. Wick-Lube System for Longer Gear Life extends gear life with simple lubrication. All models include Gear Oil and Gear Oil Gun. Insulated Throttle Handle Reduces cold air transmission to operator's hand. Handle position is adjustable, increasing comfort and efficiency. Robust 1.3 hp Air Motor 1.3 hp (970 W) governor-controlled air motor delivers powerful, efficient performance. Convenient Spindle Lock Allows quick and easy change of grinding wheel or abrasive disc. Less downtime!