350,000 - 400,000. The operation noise level is as low as 59 dB. Individually tested and tuned to ensure vibration-free and chatter-free. The item "Lot of 4 Ceramic Dental Turbines for W&H Synea TA97 Handpiece, 90 Day Warranty" is in sale since Monday, December 3, 2018. This item is in the category "Business & Industrial\Healthcare, Lab & Dental\Handpieces & Instruments\Dental Handpieces".The seller is "firstamd" and is located in Hockessin, Delaware. This item can be shipped worldwide.