Materials: AISI440c, AISI420, Si3n4 Precision: ABEC-1, ABEC-3, ABEC-5, ABEC-7 Noise & Vibration: Z1, Z2, Z3, Z1V1, Z2V1, Z2V2, Z3V3 Lubrication: Sri#2, SRL, PS2, M28, B325, etc. Aligning: Non-Aligning Bearing Separated: Unseparated