Cartridges are easily replaced in your practice helping you reduce costs and down-time. The replacement cartridge incorporates the spray holes to guarantee cartridge and water spray always work well together NSK “ISB” Integrated Shaft Bearingsearings forms the inner race. Unification of the shaft and the inner race provide higher rigidity which in turn reduces vibration and guarantees more accurate and consistent cutting. The patented NSK Clean Head System is a special mechanism designed to automatically prevent the entry of oral fluids and other contaminants into the high speed handpiece head prolonging the life of the bearings.