The Next-Generation ZWO EFW

Refinded Design · Anti Light-Leak Protection · Built for Astrophotography
A re-engineered internal design helps reduce light leakage, while the refined mechanics deliver smoother, more consistent rotation.

The exterior has been subtly streamlined, giving the wheel a cleaner and more cohesive look.
Nothing dramatic. Just better in the ways that matter — so your imaging workflow stays steady, reliable, and quietly improved.

The ZWO Electronic Filter Wheel (EFW) is available in four models, supporting the following filter sizes:
  Ø1.25″/31 mm filters
  Ø36 mm filters
  Ø2″ filters 
  Ø50 mm square filters

Compatibility

Engineered for full compatibility with all ZWO filters for dependable image quality.

Power & Connectivity

Draws only 120 mA at 5 V and runs entirely from a single USB  connection—no external power supply needed.
Connects to your imaging system via the built-in USB-C port using the included USB 2.0 Type-A to Type-C cable.

Software Support

Works seamlessly with ASIAIR, ASIStudio, ASCOM, and the ZWO SDK for flexible control across platforms.

Driver-Free Design

True plug-and-play design with no driver installation required.

Anti Light-Leak Design

In deep-sky imaging, even small amounts of stray light can compromise your final image.

The new ZWO EFW introduces a series of structural refinementsd to eliminate light leakage from all directions
★ Upgraded Sealing Structure 
A re-engineered slot-fit chassis provides a tighter mechanical interface between the top and bottom covers, minimizing potential ingress points for stray light.
★ Dual Light-Blocking Protection
Newly added light-blocking pads on both lateral connection points creates additional optical barrier,  helping maintain clean, uniform frames during long integrations.
★ Fully Enclosed Motor Compartment

The motor assembly is now fully sealed, improving both light isolation and environmental resistance for more stable operation over time.

Refined Exterior Design

The new ZWO EFW features a refined laser-engraved finish and cleaner logo detailing, offering improved visual clarity and a more modern, professional look.

Interface Upgrade

The new ZWO EFW replaces the legacy USB Type-B connector with a modern USB-C interface, providing a more robust, reliable connection and simplifying plug-and-play integration with your imaging system.

Lightweight & Rigid

The new ZWO EFW uses a CNC-machined aluminum alloy body for a lighter, more rigid structure.
The internal filter carousel is made from 6061 aluminum alloy, reducing weight while maintaining excellent strength and stability. The result is a compact, durable design engineered for smooth, reliable operation.

Stable & Durable

The new ZWO EFW is equipped with a high-precision stepper motor, ensuring consistent rotation and stable operation across extended imaging sessions.

Automated Filter Switching

The new ZWO EFW features a motorized, 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.

Connection

ZWO EFW-5×1.25-25
ZWO EFW-8×1.25-25

ZWO EFW-5×2-25
ZWO EFW-7×2-25
ZWO EFW-7×36-25

50mm 7 Slots

Diagram

What’s in the box?