Magura DLO cartridge

Sarnian

I recently brought some Magura odur forks just to see me through until after Christmas (as my forks suddenly packed up on me) but I am so impressed with them I have decided to keep them on. The thing Is I want to get the handlebar remote lockout, I have found the lever but can't find the cartridge that the manual says you need.

Does anyone know were I could get one from.