BRONZE
GRADE
HIGH-SPEED BEARINGS
Precision steel ball bearings Nylon retainer cage Single removable rubber shield
SILVER
GRADE
SIX-BALL BEARINGS
Six Precision steel balls Nylon retainer cage Single removable rubber shield
GOLD
GRADE
CERAMIC BEARINGS
Precision Ceramic Balls
Coated Races
Nylon retainer cage
Single removable rubber shield