5mm T2 extension

T2 extension rings have different use:

1. can be screwed to optical accessories (such as field flatteners or focal reducers) to bring the camera sensor at the right distance from the lens (to optimize performance)
2. can be used to separate the mechanical accessories that, when used together, can touch and then not work properly (eg an off-axis guider could touch a filter wheel and it could prevent its rotation searching for a guide star)

T2 extension installed (together with the M48 female to T2 male adapter) between camera and corrector in order to correctly set backfocus.

T2 extensions can be screwed together. In order to set the perfect thickness you need, you can also add the T2 1mm and 0.5mm spacers in between.