Ritchey:

Designed for bicycles with semi-integrated ZS headsets, the Classic Press Fit Upper Headset features full-complement stainless steel angular contact cartridge bearings packed with Ritchey high-webbing grease. Wrapped in our timeless high-polish finish, the Classic Semi-Integrated ZS Upper headset adds that classy detail your bike deserves.

Material: alloy
Stack height: 10.1mm
Headtube ID: 44mm
S.H.I.S.: ZS44/28.6 (1 ?)
ZS44/28.6 (1 ?) bearing: 41.0/30.15/7mm 45/45 – sealed cartridge (ACB)
Top cap included
Weight: 51g
Colour: high-polish silver