Moonlite Focuser Mounting Spacer

This is a spacer for the Moonlite Focuser. I have a Skywatcher MN190 telescope and the spacer that came with the Moonlite focuser was 13mm thick, which was fine until I decided to add a filter wheel at which point I needed a few more mm of back focus so I removed the 13mm aluminium spacer for a 3D printed one of 3mm.

Critical focus on the MN190 is 0.08mm meaning that if you move from the focused position by more than 0.08mm your image will be out of focus, so any spacer between the focuser an