ION - Precision ABEC-5 "RED SEAL" Deep Groove Radial bearing SET (2 pcs)
Bearing Upgrade Kit Includes: 1 Set (2 Bearings as pictured above).
If a Retailer/Vendor does not specify which ABEC rating, it's likely that's it's ABEC-1, or even lower(not rated)! Many helicopter kits come standard with ABEC-1 steel bearings. ABEC-5 bearings are much tighter in tolerance, thus providing much higher accuracy, better efficiency, longer life, and smoothness.
NOTE: The chart below shows the average tolerance difference between ABEC-1, ABEC-3, and ABEC-5.