These super fast speed bearings feature impact resistant removable nylon cages and removable shields as well as heat resistant chromium steel rings. High speed Spitfire lubricant tops it off for long lasting speed guaranteed.
ABEC 3 - The ABEC scale is essentially a measurement of bearing tolerance for high precision bearings as dictated by the Annular Bearing Engineering Committee (ABEC). The scale runs from ABEC 1 through ABEC 9 using odd integers only. Essentially, the higher up on the scale a bearing is rated the tighter the tolerance is.
Tighter bearing tolerance means that the bearing moves with less resistance at high speeds, giving you a bit more roll for your push. In general most ABEC 3 or ABEC 5 bearings have steel races (shell of the bearing) with hardened steel ball bearings, and most ABEC 7 or ABEC 9 bearings feature steel races with super hard (much harder than steel) ceramic or titanium bearings.