I got a pair that fit a Fantic Rally for mine, Haines the Fantic dealer sell them you need one with R/H thread & one with L/H thread I think they were £30 a pair they give a good view.
These work really well and just clamp to the handlebars which reduces the risk of damage to the lever mounts in an off 👍 www.wemoto.com/parts/picture/vm-e141
I have Double Take Enduro mirrors installed on all my offroad bikes including my TT-R250. While they are definitely expensive once you add the requisite RAM mounts and extensions, they offer a great deal of adjustability, and are nearly indestructible (personally crash-tested more times than I'm willing to admit!):
Thanks for the replies. I took a chance with a pair of mirrors on ebay. They come with adapters for various threads. Look ok and have been used on a day trail riding in Wales. Cost £28 for the pair.