Bones Swiss Bearings Ceramic
* Features grade 5, silicone nitride, hot isostatically pressed ceramic balls.
* Higher quality steel races and a superior surface finish.
* Single non-contact removable rubber shield for easy cleaning and less friction.
* High speed nylon ball retainer for greater strength and speed.
* Pre-lubricated with Speed Cream™ racing lubricant.
* Skate Rated™ clearances, tolerances, materials and lubricant provide the best performance and durability possible.