The ZWO EFW 5 x 1.25-inch Electronic Filter Wheel (Next-Gen) packs professional automated filter switching into the smallest, lightest form factor possible. Perfectly sized for portable setups, this "Mini" wheel accommodates up to five 1.25" mounted or 31mm unmounted filters. The re-engineered chassis introduces superior anti light-leak protection, utilising a slot-fit design and dual light-blocking pads to ensure your long-exposure dark frames remain pristine. The exterior has been refined with a sleek, laser-engraved finish and now features a modern USB-C interface, providing a more robust and reversible connection than previous generations.

Despite its compact size, the 5-position EFW is built for precision. A high-quality Japanese NPM stepper motor drives the internal carousel via a friction drive system, ensuring zero backlash and whisper-quiet operation. Weighing approx 300g and boasting a 20mm optical thickness, it integrates seamlessly into your imaging train without causing balance issues. Powered by a single USB-C cable connected directly to your camera's hub, this ZWO EFW simplifies cable management while delivering the reliable performance needed for automated LRGB or narrowband sequencing.

Anti Light-Leak Design
In deep-sky imaging, stray light is the enemy. The new ZWO EFW introduces a re-engineered slot-fit chassis and dual light-blocking pads on lateral connection points to create a superior optical barrier. Combined with a fully sealed motor compartment, this design minimises potential ingress points, helping you maintain clean, uniform frames during long integrations.

Interface Upgrade
Reliability meets modern connectivity. The next-generation EFW replaces the legacy USB Type-B connector with a robust USB-C interface. This upgrade simplifies cable management with reversible plugging and ensures a more stable data connection for your imaging system.

Compact & Lightweight
The 5-position EFW is the smallest wheel in the ZWO lineup. Crafted from CNC-machined aircraft-grade aluminium, it is incredibly rigid yet weighs approximately 300g. This featherweight design is ideal for portable rigs and smaller refractors where keeping weight down is critical.

Automated Filter Switching
The ZWO EFW features a motorised, bidirectional filter-wheel drive with precise position indexing. When paired with control software such as ASIAIR (sold separately), it enables automatic filter changes during a scheduled imaging session — enabling fully unattended, hands-free astrophotography.

 

Key Features

• Compact 5-Position Carousel: Holds up to five 1.25" mounted or 31mm unmounted filters, perfect for essential LRGB or narrowband sets in a ZWO EFW.

• Anti Light-Leak Design: Features a re-engineered chassis with dual light-blocking pads to eliminate stray light artifacts.

• USB-C Interface: Upgraded to a modern USB-C connector for a stable, reversible, and durable connection to your imaging system.

• Featherweight Design: The lightest in its class (approx. 300g), this electronic filter wheel places minimal strain on your focuser.

• Precision Motor: Equipped with a Japanese NPM stepper motor for reliable, vibration-free filter positioning.

 

 

What's in the Box

• EFW Body

• 1.25" Cover

• T2 Nosepiece

• 1.25" Holder (with cover and 2 screws)

• M42M-M42M Adapter (Male-to-Male)

• Bag of Filter Masks

• USB 2.0 Cable (2m)

• USB 2.0 Cable (0.5m)

• Phillips Screwdriver

• M2.5*6 Screws

• M2*4 Screws

• M4*12 Screws

How to Use the EFW

To operate the electronic filter wheel, simply connect it using a USB 2.0 cable and install the ZWO ASCOM driver. Within your imaging software, select either “ZWO Filter Wheel (1)” or “ZWO Filter Wheel (2)”—both options work identically and are designed to support multiple filter wheels in a single setup.

 

 

 

 

 

 

 

 

 

 

 

 

How to connect the camera and telescope:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Specifications

Number of Positions	5 x 1.25" or 5 x 31mm (unmounted) filters
Thickness	20mm
Weight	~300g
Power Supply	USB Power (120mA max @ 5V)
Motor	Stepper
Material	CNC-machined aircraft-grade aluminium
Compatibility	Ideal for ZWO cooled cameras and ASIAIR setups
Vignetting Limits	1.25" filters down to f/5, 31mm filters down to f/2

 

Recommended Accessories

	ZWO NEW 1.25-inch LRGB Filter Set Get started with monochrome astrophotography by using these dedicated filters to separate light into LRGB wavelengths for better detail.
	ZWO Narrowband 7nm 1.25-inch Filter Set Get started with SHO imaging with the ZWO Narrowband 1.25" Filter Set. Narrowband filters improves contrast between nebulae and reduces effects of light pollution.
	ZWO 850 IR 1.25-inch Filter Add a IR-Pass filter to enhances contrast in planetary imaging (great for Mars, Jupiter, Moon).
	ZWO ASIAIR Plus - 256GB Model Control your new astronomy camera with the ZWO ASIAIR Plus. This device enables you to control, guide, filter control and power your camera without using a computer. Perfect for streamlining and cord management!

 

About ZWO Optical

Established in 2011, ZWO Optical is a fast-growing global astroimaging camera powerhouse based in Suzhou, China. Known for its iconic ZWO ASI 120MM Monochrome CMOS Camera, the first-ever planetary CMOS camera to beat a CCD in the early 2010s, ZWO has  pioneered new astroimaging technology with revolutionary new features, including USB 3,0, cooled systems, ADC and more. Today, ZWO Cameras is known by every passionate astrophotographer and is available in over 25 countries world-wide. 

Product Code: EFW-5x1.25-25