Super fast. Durable. Guaranteed. Spitfire Classic Bearings are fast, long lasting speed bearings. You get impact resistant removable nylon cages. Heat resistant chromium steel rings. Blue removable shields. All made with exclusive high speed Spitfire lubricant. Spitfire Classics are built to last, and are tested, ridden, and approved.
ABEC 7 - 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.