Air Turbines unique air motor design delivers "air power" - constant high speed and torque under variable loads - for increased accuracy and extended, cutting tool life. A patented motor govenor maintains tool speed as load increases for. Fewer moving internal parts results in greater reliability and fewer repairs, virtually eliminating problems associated with other spindle speeders - no vanes, no gears, no oil. The Series 600 spindles provide high cutting speeds for finer-finishes and faster production rates. Durable triple, ceramic bearings ensure reliability and precise accuracy. Totally oil free operation, no lubrication or mist. Made to order in USA. Delivery 7-10 days. Available Speeds: 30,000 / 40,000 rpm Max. Power Hp (Watt): .4 (300) / .45 (340) Air Consumption: 5.5-21.5 / 6-21.5 cfm max. Requires clean, dry, oil-free, 90psi. AIR ONLY ER11 Collet Sizes: 1/4" standard, 7mm maximum TIR: <0.0004" (<10΅m) Sound Level: < 64 dBa Dimensions: Ψ 2.13" x 6.42"OL, 3/4" Straight Shank Weight: 43.2 oz. Standard Equipment included in kits: Spindle Air Filter/Regulator Detachable Coolant Guard 1/4" ER11 Collet Wrenches Carrying Case Specify spindle speed below.