Chuck Type: latch type chuck. Bur Applicable:2.345-2.355mm. Provides sufficient force at low speed. Available for various E-type motors in accordance with ISO standard. The sale of this item may be subject to regulation by the U.Food & Drug Administration and state and local regulatory agencies. If you have questions about legal obligations regarding sales of medical devices, you should consult with the FDA's Center for Devices and Radiological Health. This dental items is not meant to replace your doctor diagnostic. It is mainly for your piece of mind and comfort.