Hello and welcome, there are a few companies that makes rear lights Acerbis is one but they need a bit of adapting to do becaue so far I haven't yet seen one specifically designed as standard fitting replacement for the XTX, most people who did that, had to chop off part of the rear fender and fitted some custom bracket in order to make the light fit.

Buck he is one of them he did a great job on his bike I am sure he will give us some light on the matter tomorrow when he reads this post.