ZWO 2-inch Filter Drawer with 21mm ring design is independently developed by ZWO, which includes M42 * 0.75 male thread (camera side) and M48 * 0.75 female thread (filter end), M48 * 0.75 female thread (telescope side) as well.
The double strong magnets create stronger adsorption, easier installation and removal.
There is a lock screw on the side of it, which is helpful on adjusting the tension to eliminate the gap; a double insurance for users.
With the ability of double strong magnetic adsorption, it is more convenient and much easier to install or remove the filter drawer.
The filter drawer also comes with the M48-M42 adapter. You can use it with your camera or your telescope.
M42 * 0.75 male(external) thread (camera side)
M48 * 0.75 female(internal) thread (filter end)
M48 * 0.75 female(internal) thread (telescope side)
Suitable for 2-inch astronomical filters