Bicycle headset bearings(also called ACB, ACB bearings). Bearing inner ring and outer ring has 45°/45°, 36°/45°, 36°/36° tapered chamfer angle.
SS MH-P08F(TH-870ES, 30.6×41.8×8 mm, 45°/45°, single-sealed), it is the same size with SS MH-P08H8 and made of stainless steel SUS440 races & balls, but inner ring is different from MH-P08H8. P08H8F inner ring with a small lip. This bearing is application for some 1-1/8" & 1-1/4" specialized headsets.
SS MH-P08F(TH-870ES) is application for 1-1/8" internal headsets or scooter headset.