45 x 45 degree "ACB" measures: 30.5mm ID x 41.8mm OD x 6.42mm W

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. Dual lip sealing system.

Replaces the UPPER Headset Bearing in the following SPECIALIZED frames:

2009 and later Epic frames
2009 and later Era frames
2008 and later Stumpjumper carbon frames
2009 and later Safire frames
2010 and later Enduro frames
2010 and later Stumpjumper alloy frames
2013 and later Camber frames
2013 and later Myka frames
2011-12 Tarmac frames

Bearing is also known as:

MR042
870E
MR121
MR070
MR084
MR116
TH-870E
MH-P08

BEARINGS SOLD INDIVIDUALLY