oll-Line SPEED MAX Professional Bearings 

Type:   Custom Roll-Line 
Axle Center Bore:   7mm = KSTCUMB
   Be sure you identify which size Axles you have and which
      size (7mm or 8mm) Bearings are needed. NOTE: Speed MAX is only available in 7mm.
Outside Diameter:    22mm (the same for all Roller Skate Bearings)
Number of Balls:   Ultra Precision 8 Balls
Special Features:   Carbon Impregnated Ball Crown Cage Ring 
with 1 Metal Shield 
ABEC Rating:   ABEC 9
One (1) Set=   16 Bearings