The ZWO 2″ Filter Drawer with M48 / M42 Connections and 21mm ring thickness has been independently developed by ZWO. It includes an M42 * 0.75 male thread on the camera side and M48 * 0.75 female thread on the telescope side, and it is suitable for 2″ filters (the drawer has got a M48 * 0.75 female thread).
The main idea of a filter drawer is to use it with a colour camera where there is usually no need for lots of various filters, usually just few filters need to be swapped between sessions. One of these would normally be either a UV/IR-cut off or light pollution filter (CLS, UHC etc) and the other filter would be a narrowband, i.e. H-alpha or a Dual Band filter.
The double strong magnets create stronger hold, easier installation and removal.
There is a lock screw on the side of it. The locking function is helpful on adjusting the tension to eliminate the gap, which is a double insurance for users.
With the ability of double strong magnetic pull, it is more convenient and much easier to install or pull out the filter.
The filter drawer also comes with a M48-M42 adapter. You can use it with your camera or your telescope.
66mm (height) * 66mm (length) * 21mm (thickness)
M42 * 0.75 male thread (camera side)
M48 * 0.75 female thread (filter end)
M48 * 0.75 female thread (telescope side)
Suitable for 2-inch astronomical filters