1.Microfilter, Microfilter is to prevent particles from entering the water spray system to guarantee optimum water spray cooling at all times 2. Single Water Spray The NSK Single Water Spray effectively cools the surface of the bur with a high cooling effect. 3. DURACOAT NSK's latest surface enhancement technology, takes advantage of the non allergic and biocompatible properties of titanium to further improve durability. DURACOAT creates a smooth, scratch resistant surface which is comfortable to hold.