ZWO Mini Electronic Filter Wheel  (EFW) - 5 x 1.25″ or 5 x 31mm
ZWO Mini Electronic Filter Wheel  (EFW) - 5 x 1.25″ or 5 x 31mmZWO Mini Electronic Filter Wheel  (EFW) - 5 x 1.25″ or 5 x 31mmZWO Mini Electronic Filter Wheel  (EFW) - 5 x 1.25″ or 5 x 31mm
ZWO Mini Electronic Filter Wheel  (EFW) - 5 x 1.25″ or 5 x 31mmZWO Mini Electronic Filter Wheel  (EFW) - 5 x 1.25″ or 5 x 31mmZWO Mini Electronic Filter Wheel  (EFW) - 5 x 1.25″ or 5 x 31mm

ZWO Mini Electronic Filter Wheel (EFW) - 5 x 1.25″ or 5 x 31mm

  (14 Reviews)
✓ 2 year warranty


Out of stock due 10-15 working days

About this product

Model:  zwo_efw_mini
Part Number:  ZWO-EFW-MINI

The smallest and most lightweight 1.25" electronic filter wheel available. Only 300g!


  • Supports 5x 1.25" mounted filters or 5x 31mm unmounted filters.
  • Stepper motor made by NPM from Japan - quality and reliability you can trust.
  • Rotates in both directions for faster filter selection
  • CNC machined body from a full block of aircraft grade aluminium enabling a very thin 20mm design.
  • Powered by USB - max consumption around 150ma@5v
  • ASCOM driver

Filter to sensor distance when connected to the ASI1600 is around 10mm, you can use 1.25" filters without vignetting up to f/5 or 31mm filters up to f/2.

Includes M2 screws and washers required for fixing unmounted 31mm filters.

Important Note: 1.25" filters require threads shorter than 3mm and the height without threads must be less than 7mm.

Camera in picture not included ;-) The short USB cable pictured is supplied with the ASI1600 cameras with USB hubs.

Mechanical Drawing

What's in the box

  • EFWmini Body
  • T2 Nosepiece
  • 1.25" Holder to T2
  • T2-T2
  • USB2.0 Cable
  • M2 Screws & Washers for 31mm Filters

Downloads / Manuals

The following manuals and downloads are available for this product:


ZWO Software and Drivers


Customer reviews

Average Rating (14 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Sturdy Five Unit Filter Wheel
02 December 2023  | 

This ZWO device mates perfectly with my ASI 1600 MM Pro camera. The camera 42mm nosepiece only protrudes 0.5mm beyond the F.W. end plate - thus avoiding and interaction with the rotating filter carrier. Similarly the threaded portion of the Antila filters do not protrude beyond the rotating plate. Consequently, it is very straightforward to install the filters. The ASCOM driver was downloaded from the ZWO site and installed, and control of the filter in use from the Nebulosity environment functioned directly, after assigning labels to the filter positions. In summary, a solid unit which was easy to instal and bring into service.

Rating (max 5):  
Excellent little filter wheel
02 February 2023  | 

I'm absolutely so impressed with this filter wheel I used it with my redcat 51 and 533mc pro.
the eaf and asi air plus. I must admit I'm not the most technical person but I just plugged it in and it all fired up and worked pain free
I'm very happy and looking forward to setting up the scope and letting it run on different targets to get the most out of my rig.

Rating (max 5):  
Easy to set up
17 March 2022  | 

Great service from FLO. I chose this based on previous reviews here. Using SharpCap I just plugin the USB cable, selected the hardware config and connected. The filter positions can be defined by name, and there are five buttons at the lower rhs of SharpCap for manual filter selection, or the sequencer can be used. Now waiting for the clouds to disperse.

Rating (max 5):  
Perfect Addition
16 September 2021  | 

If like me you like to switch between objects, then this is a great addition to have, and as I am fortunate to have a permanent setup, this avoids the obvious swapping of filters as you change object, thus eliminating the possibility of dust getting into the setup.

I use OSC cameras, so with five slots, this allows me to move from Narrowband to a Moon filter!

Setup is very easy and works well with, ASCOM and PC and ASI AIR Pro ( note with the ASI air, lack of ability to rename the slots, so have a plan!)

Rating (max 5):  
Great size for ASI533MC
01 September 2021  | 

I bought this to compliment my ASI533MC as I want to be able to swap between a UV/IR filter and the Optolong L-eXtreme filter without introducing dust into my system. The system is well sealed and does not offer any open spaces to allow dust in so long as the rest of the imaging train is affixed.

ZWO include a screwdriver so you don't need to use any other tools to open up the filter wheel. On the inside, there are numbers against each filter slot which corresponds with the index position within whatever software you use to drive the filter wheel. Once I installed my filters, I wrote down the filter position and filter type onto a sticky label and affixed to the outside of my filter wheel so I can remember which filter is where (more on this later). The 1.25" filters are a perfect size for the ASI533MC as the filter wheel is attached directly to the camera.

The system plays nicely with my ASI Air Pro as you would expect. At arms distance the filter wheel makes zero noise when indexing. Sadly, the ASI Air software doesn't allow you to freely name your filter (there's options for L, Dark, R, G, B, S, H, O etc) so right now the L-eXtreme is shown as "2" to indicate the index position number, hence why I put the sticky label on the filter wheel!

All in all, this filter wheel is well worth the money and I cannot see any downsides.

Rating (max 5):  
11 August 2021  | 

Solid, compact and very quiet in operation. Have used with Astronomik filters without issue.

Rating (max 5):  
Zwo Mini Electronic Filter wheel
08 November 2020  | 

Great product, absolutely silent and smooth operation, fair price and fast delivery by First light optics to germany. Many thanks!

Rating (max 5):  
ZWO Mini Filter Wheel
13 July 2020  | 

Bought this to use with Optolong and ZWO filters together with my ASI1294MC Pro .
Really excellent filter wheel and would highly recommend it.

Rating (max 5):  
Great value for money.
07 June 2020  | 

It's hard to get something as good for this money. Very good build quality and works perfectly with my ASIAIR. Highly recommended.

Rating (max 5):  
Solid piece of kit
25 May 2020  | 

Pretty solid piece of kit. Does exactly what it says on the tin. Price is a bonus. Iíve this attached to an ASI 1600MM and a ZWO OAG. All fits together nicely and worked straight out of the box.

Read all 14 customer reviews...


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