The S-Max M series contra-angles have dramatically improved durability, and feature an updated internal body design and chuck mechanism. They are NSK's next-generation standard - a marriage of ergonomic sophistication and smooth cutting feel. Specifications: 4:1 Reducing Max Speed: 10,000 min-1 Head Size: Ø9.6 x H 13.4 mm For: CA Burs (Ø2.35) Stainless Steel Water Spray: Single Spray Features: Cellular Glass Optics Clean Head System Push Button Chuck