DIY HS Bearing - 1 1/8 41.8x8mm 45x45

Headset bearing 30.5mm x 41.8mm x 8mm 45deg x 45deg
TH-870 with step on inner chamfer
BMC TM01. Some Focus road bikes, Specialized road and MTB bikes
AKA TH-870E, MR121 MR042 P08F
Replaces MR155 TH-870/DJ