Open-type cartridge , easy to repair. Using the Barton bearing, durable. Go through dynamic balance, cartridge smooth rotation, low noise, long life. High speed handpiece, 3 way spray. Air pressure at the back end of HP:0.25-0.27Mpa. Rotation Speed? 300.000rpm. Chuck type: Push button. All the items are inspected for damage or defects prior to leaving our warehouse. We accept the returne within 14 days after the item is received. Pls make sure the item is in original condition. Without this information, the return won’t be processed. 510(K) Number: K181691 Regulation Number: 872.4200 Classification Product Code: EFB Subsequent Product Code: EGS.