I am currently about to start building a light box for a RC10 carbon fibre tube scope. Just wondering if anyone here who has one of these can confirm the outside diameter of the front of the OTA. The guy I am building it for is away from his scope and probably won't be back for a couple of weeks and wants to pick up the light box from me when he comes through Adelaide, so obviously he cannot measure it. I have made light boxes for the aluminium versions of the RC10 and that measurement is around 300mm, to trust that the carbon fibre is the same is a tad fool hardy, so I want to get it right.