Rivendell special made handlebar by Nitto.
Based on the Albatross handlebar, Bille bar has shallower rise and wider width. Most significant design point is the long gripping length - this allows you to fit variety of trigger or thumb shifters.
Diameter: 25.4mm (Stem) / 22.2mm (Grips)
Bar-end inner diameter: 19.5mm
Width: 580mm (centre to centre)
Made in Japan