440C stainless steel angular contact headset bearing.
Dimensions: 50mm x 62mm x 8mm
Angles: 36x45 deg

Frequently used as a lower headset bearing on Giant Reign E+ frames

Part numbers this bearing is known by:

TH MR229

440C stainless steel balls and races provide long life and superior corrosion resistance in applications and environments that may be less than ideal. 440C has the highest strength, hardness, and wear resistance of all the standard 440-series stainless alloys with high carbon content.