The AO/OAG Autoguider Extension Tube by Starlight Xpress:
Although the OAG unit was originally designed as an add-on to the USB filter wheel, there are many users of single-shot color cameras who would like to use the OAG without the need for a filter wheel to be included. Starlight Xpress has now introduced extension tubes to permit the OAG to focus correctly when attached directly to an SXV or SXVR camera. The longer tube is designed for use with most of our camera range, while the shorter version is specifically for the SXVR-H18 camera, which has a deeper back focal length OPT Product Number: SX-AO/OAG-EXT Photo depicts a generic image of a Starlight Xpress Extension tube mounted. Actual product appearance may vary and OAG is not included.