This model of the ZWO EFW Electronic Filter Wheel has a carousel with eight (8) filter positions and accepts either 1.25" threaded filters or 31 mm unthreaded filters. The 1.25" filters thread into place, while the 31 mm filters require M2 screws and washers (included) to fix them in place. Filters are sold separately, just make sure your 1.25" filters have threads that are shorter than 3 mm in length, and all filters are less than 7 mm high. By the way, it might help you to know that 1.25" filters won't vignette on scopes with a focal ratio of f/5, while 31 mm filters won't vignette on scopes with a focal ratio as fast as f/2.
The ZWO EFW Electronic Filter Wheel body is CNC machined from an aircraft grade aluminum block. The thickness of the EFW is just 20 mm on the body itself, while the base is 33 mm. The height of the filter wheel is 152.5 mm (6").
The EFW stepper motor is made by NPM in Japan, making it a reliable component of this filter wheel. The Electronic Filter Wheel can be rotated in either direction for quicker filter selection. Just one USB cable powers the filter wheel, with power consumption at approximately 120mAh @ 5V. If you have an ASI Cooled camera, you can plug the cable into its USB hub.
What's in the Box?
- EFW body with 8 position carousel for 1.25" or 31 mm filters
- 1.25″ cover
- T2 nosepiece
- 1.25″ holder(with cover and 2 screws)
- T2-T2 adapter(male)
- A bag of filter masks
- USB2.0 2m cable
- Phillips screwdriver
- A bag of M2 screws