8 Bearing set 9 Sector with ceramic balls.
Ceramic is lighter, durable and fast than steel balls.
7 Black Ball Ceramic Bearings - Silicon Nitride Ceramic
Extra Hard, High Density Ceramic Balls-Lighter than Steel
Corrosion Resistant, Waterproof Balls
Removable Rubber Shield for Easy Cleaning
Nylon Ball Retainer with Grease / Oil Mix for Speed & Longevity
Ceramic does not break down like steel and eliminates steel debris
Ceramic balls actually keep the steel races clean by crushing debris and continually polishing the races