Ritchey:

The Ritchey Comp Cartridge External Cup EC Threadless Headset features a cartridge bearing, smaller upper bearing to save weight, while the lightweight, precision-machined aluminum cups are deep for solid insertion.

Material: alloy
Threadless
Stack height: 32mm
Stack height upper: 18mm
Stack height lower: 14mm
Headtube ID: 34mm
S.H.I.S. upper: EC34/28.6 (1 ?)
S.H.I.S. lower: EC34/30 (1 ?)
EC34/28.6 (1 ?) bearing: 41.8/30.15/8mm 45/45 – sealed cartridge (ACB)
EC34/30 (1 ?) bearing: 44/30.5/8mm 45/45 – sealed cartridge (ACB)
Top cap included
Weight: 126g
Colour: black