Master Power 3, 000 - 4, 000 blows per minuteRated for continuous production usePrecision feathering throttle for positive bit control360 exhaust deflector. No blow back of chips, air, dustPatented interlock quick-change spring holds bits securely, permits easy, quick bit changes Replaceable steel nose bushing saves on cost of replacing complete barrel (MP5164 and MP5168) Side to center 1332 (27.8mm)