B2525 maybe?
https://www.planetx.co.uk/i/q/HBNIB2525/nitto-b2525-commuter-handlebar
I thought they were 600mm but may have misremembered.
@TM started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
B2525 maybe?
https://www.planetx.co.uk/i/q/HBNIB2525/nitto-b2525-commuter-handlebar