Description FSA Headset Bearing, 30.5mm x 41.8mm x 8mm,1-1/8″ x 45°/45° (MR121). 45°/45° Sealed Angular Contact Bearing. 1-1/8″ Fits upper of: Orbit C-33, and Orbit C-40 Fits upper and lower of: Impact, Impact PC, Orbit CE, and Orbit C series of headsets MR121 (870E-RS)
