If the NSK Speed Reducer is connected between the motor and the spindle, it reduces the rotating speed and increases the torque while keeping the motor speed unchanged.• Maximum allowable motor speed for the spindle: 30,000rpm• Maximum rotating speed at the cutting tool: 7,500 rpm• Speed Reduction Ratio: 1/4• Speed Reducing Mechanism: By planetary gear system• Weight: 5.29 oz.• NSK Catalog Number: AS81822P