ZWO 5x 2'' Electronic Filter Wheel  (EFW)
ZWO 5x 2'' Electronic Filter Wheel  (EFW)ZWO 5x 2'' Electronic Filter Wheel  (EFW)ZWO 5x 2'' Electronic Filter Wheel  (EFW)
ZWO 5x 2'' Electronic Filter Wheel  (EFW)ZWO 5x 2'' Electronic Filter Wheel  (EFW)

ZWO 5x 2" Electronic Filter Wheel (EFW)

  (2 Reviews)
✓ 2 year warranty


2x in stock shipped 1-2 working days

About this product

Model:  zwo_efw-5x2
Part Number:  ZWO-EFW-5x2

New ZWO 5x 2" electronic filter wheel (EFW).

The filter wheel body is CNC machined from a single block of aircraft grade aluminium for maximum strength and rigidity. It also features a quality Japanese-made stepper motor.  

Only 20mm thickness.

Also available in 7x 2" variant. 


  • Supports 5x 2" mounted or 50.4mm (+/- 0.5mm) unmounted filters.
  • Quality Japanese-made stepper motor.
  • Rotates in both directions for faster filter selection.
  • CNC-machined from a single block of aircraft grade aluminium.
  • Powered by USB - max consumption around 120ma@5v.
  • ASCOM driver.

There is no need for multiple cables to power this wheel, just one USB cable will suffice. The maximum power requirement is approximately 120mAh @ 5V, so it can be operated from the Cooled camera's USB2.0 port.

When connected to a ZWO ASI6200, the distance from the filter to the sensor is about 18mm

ZWO recommend their 2″ RGBL filters which work well with the ASI6200MM Pro camera and provide nearly 1:1:1 RGB colour balance.

The requirements shown below must be met if using non-ZWO 2” filters. 

Mechanical Drawing

What's in the box

  • Filter wheel body
  • USB2.0 – 2m cable
  • Bag of M2.5*6 screws (6pcs / bag)
  • Bag of filter masks for 50mm filters (7pcs / bag)
  • Phillips screwdriver
  • Bag of M2*4 flat screws (23pcs / bag)
  • M54M-M48F adapter
  • M54M-M42F adapter

Downloads / Manuals

The following manuals and downloads are available for this product:


ZWO Software and Drivers


Customer reviews

Average Rating (2 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Deisng Could be Better... Requires DIY to Stop Light Leaks
11 October 2023  | 

First off, Royal Mail tracked-24 delivery lost my EFW in shipping, which was frustrating. Fortunately, FLO shipped me a new unit by courier at no extra cost. Thanks FLO!

I had read online that the ZWO EFW leaks light, and sure enough it leaks it like a sieve. This is a big problem if you wish to take dark frames during the day, but also not good in general. I screwed my camera (ZWO ASI 294MC-PRO) directly into the EFW by using the supplied M52-M48 adapter, it fits nicely but bizarrely this setup leaves 8 holes (!!!) exposed in the rear, which let light directly into the unit. Presumably these holes are there so that you can bolt different types of camera onto the EFW, but I bet that most users screw their camera in, leaving the holes exposed. Taping over the holes with light-blocking sticky tape solves the problem, but is very ugly, and honestly I'd say that ZWO should redesign the EFW to remove the holes. Is it fit for purpose? Yes, once the holes are taped light leakage is minimal, and NINA plays beautifully with it.

Rating (max 5):  
So much easier with one of these.
18 March 2021  | 

Setup was nice and simple Had to make a small adjustment to my train to get back to 55mm back focus. Once that was done I ran into a slight issue in use. I calibrated the wheel and it all seemed ok but I got a message saying "It is detected that carousel is slipping or blocked. There is possibility that the space between motor stalk/shaft might be too loose or too tight or the central fixing screw of the carousel is too tight” The answer was in the message. undid the cover plate, in the centre of the wheel is a screw covered in black felt. Remove the felt carefully adjust the screw with a flathead screwdriver. For me it was just a little to tight. Once done I calibrated again, problem solved.

My rig required a re-balance as it adds some weight to the rear of the imaging train.

Very nicely engineered bit of kit.


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