1-1/2" stainless steel, Angular Contact Headset Bearing used on many Specialized frames, including Venge, Tarmac, and Aethos models. Used as lower bearing only on many Venge frames, but used as both upper and lower on Venge 2019 and on Tarmac SL7. Used as lower headset bearing on Aethos frames.

Dimensions: 40.5mm x 49.5mm x 6.5mm. Angles: 45x45 deg

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.

Part numbers this bearing is known by:

ACB 4545 405495 SS
ACB495H6.5
HSS 6011
S222500014
S162500005