The new 36mm EFW (Electronic Filter Wheel) independently developed by ZWO for astronomical mono cameras. With the larger body and the newly-added screw holes on the covers, it will give a much easier and more fixable way to connect to ASI cameras.
The body is CNC milled from an aircraft graded aluminum block. It is made with high quality and thin with the thickness of only 20mm. The heart of the EFW uses the quality stepmotors produced by NPM, Japan, which can be very trustworthy. When photographing, you can rotate the EFW in both counter clockwise or clockwise direction for filter selection. The whole operation process is rather convenient and efficient.
All ZWO 36mm filters can be perfectly supported by this EFW. But if you use filters from third party, then please make sure the thickness of the filter should be between 1.5mm and 3.0mm (the thickness of the filter frame is 1.8mm).