ZWO Premier EFWmini 5-position Filter Wheel for 1.25" and 31mm Unmounted Filters
The Next-Generation ZWO EFW Refined 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
Compatability
Engineered only 120mA at 5V and runs entirely from a simple 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.
Drive-free design.
True plug and play design with no driver installation required.
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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 refinements 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 aluminium alloy body for a lighter, more rigid structure.
The internal filter carousel is made from 6061 aluminium 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-5x1.25 -31
ZWO EFW8x1.25-31
Diagram
What's in the box?
