Thanks, I will get lots of penetrating oil on it first.I have a similar looking bottom bracket, by memory it is a Raceface, it has 12 indents. I could not identify a tool, so I worked out a 32mm nut was a bit bigger and I ground the edges down until it fitted and would move the bottom bracket without damaging the soft aluminium. Hopefully the bottom bracket was put in with the anti-seize compound. Very good luck with it.