Ritchey:

For bikes featuring integrated headsets (such as the Ritchey Road Logic and Swiss Cross), the Comp Integrated IS Headset stands above all others. The Comp features semi-cartridge high-quality bearings.

Material: steel
Stack height: 6.8mm (1 ?) / 6.7mm, 16.6mm (1 1.5″ tapared)
Stack height upper: 6mm (1 ?) / 5.15mm, 15.3mm (1 1.5″ tapared)
Stack height lower: 0.8mm (1 ?) / 1.55mm, 1.3mm (1 1.5″ tapared)
Headtube ID upper: 42mm
Headtube ID lower: 42, 52mm
S.H.I.S. upper: IS42/28.6 (1 ?)
S.H.I.S. lower: IS42/30 (1 ?), IS52/40 (1.5″)
Bearings: semi-cartridge (SSC)
Top cap included
Weight: 75g (1 ?)
Colour: black