Bones Swiss Bearings (8 pack) towels professional competition grade speed and durability Size:31 32 professional competition grade speed and durability make Bones Swiss normally last several times as long as ordinary ABEC rated bearings speed and spinMax Impact Cage Design Non distortion custom cage keeps the balls precision spaced Micro grooves aid in oil circulationBalls Out Technology Eliminates shield and cage contact on impact for a go fast Skaters who use Bones Swiss do so because they want the very best equipment they can get and know the difference between ordinary and exceptional Best selling high end skate bearing in the U