Starizona's RASA 8 Filter Holder allows for the use of 2" filters that are unable to use the Starizona Filter Slider, such as the ZWO ASI2600 and ASI071, plus Altair, Atik, QHY, and Mallincam cameras. This filter holds comes with a 5 mm M42 spacer, giving you 17.5 mm of backfocus (the most common camera backfocus). Other spacers are available for other camera setups (sold separately). Without any spacer, the maximum usable backfocus is 22.5 mm.
To use the RASA 8 Filter Holder, simply remove the optical window that is installed in the RASA 8 and install a standard 2" mounted filter in the Filter Holder. The Holder will replace the standard camera adapter flange from the RASA and is held in place using the stock lock ring. The Filter Holder is machined with slots, allowing you access to the collimation screws that are on the RASA.