"The 3445MAX is the perfect choice for high performance finishing. This 4 1/2in. air angle grinder combines a unique motor controller that virtually eliminates overspeeding.with a powerful 88 HP motor to provide plenty of power for rust and material removal. CFM at Load 41, Air Consumption CFM 9, Disc Diameter in. 4 1/2, Tool Length in. 9 1/2, Speed RPM 12,000, Side Handle Yes, Air Inlet Size in. NPT 1/4, Min. Hose Size in. 3/8. 88 HP motor 5/8in. spindle, #11 thread Rear exhaust with piped-away option Composite grip for improved comfort Locking lever with tease throttle Lightweight design"