1.They stay cool during those long grooming days. 2.Less expensive than replacing the entire blade. 3.Made from extra strong zirconia ceramic material to resist chipping and breaking. Suitable for most types of hair clipper: (WMARK NG-101 555 666 777 888) ( 5-STAR SENIOR, , II.TAPER 2000,PRO BASIC, and Other similar model) Name: Zirconia Ceramics Specification: 28 teeth Gramme weight: 6.7g Colour:white Material:ceramics Size:4.2 * 2.3cm Package Contents: 5 x Ceramic Blade 5 x box Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.