ZWO EFW mini (5 x 1.25″or 5 x 31mm)The ZWO Electronic Filter Wheel Mini weighs only 300 grams, it is CNC machined and the optical thickness is only 20mm. It supports 5 x 1. 25" filters or 5 x 31mm filters. Compatible filters 5 x 1. 25" 5 x 31mm unmounted Ports USB Power draw 120 mA @ 5A Power supply USB cable Maximum thickness of the filter 7 mm (not including threads which must be less than 2. 7 mm) Optical thickness 20 mm Camera connection M42 x 0. 75 female Telescope connection M42