ZWO EFW 8 x 1.25″/31mm

The Next-Generation ZWO EFW
Refined Craftsmanship · Light-Leak Protection · Engineered for Astrophotography
A redesigned internal layout minimizes light intrusion, while the improved mechanics offer smoother and more uniform rotation.
The outer body has also been gently updated, giving the wheel a more polished and unified appearance.
Nothing drastic – simply meaningful refinements that keep your imaging setup stable, dependable, and subtly enhanced.

The ZWO Electronic Filter Wheel (EFW) comes in four versions, each compatible with one of the following filter formats:
- Ø1.25″ / 31 mm filters
- Ø36 mm filters
- Ø2″ filters
- Ø50 mm square filters


Compatibility
Designed to work flawlessly with all ZWO filters, ensuring consistent and reliable imaging performance.
Power & Connectivity
Consumes just 120 mA at 5 V and operates fully through a single USB connection—no separate power source required.
Links to your imaging setup through the integrated USB-C port, using the supplied USB 2.0 Type-A to Type-C cable.
Software Support
Integrates smoothly with ASIAIR, ASIStudio, ASCOM, and the ZWO SDK, providing versatile control across compatible platforms.
Driver-Free Design
A true plug-and-play system that functions without any driver installation.
Anti Light-Leak Design
In deep-sky astrophotography, even minimal stray light can degrade image quality.

The new ZWO EFW introduces several structural refinements to eliminate light leakage from all directions:
★ Upgraded Sealing Structure
A re-engineered slot-fit chassis creates a tighter mechanical interface between the top and bottom covers, reducing potential entry points for stray light.
★ Dual Light-Blocking Protection
New light-blocking pads added to both lateral connection points form an additional optical barrier, helping ensure clean, uniform frames during long exposures.
★ Fully Enclosed Motor Compartment
The motor assembly is now completely sealed, enhancing light isolation and improving environmental resistance for stable long-term operation.

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
Replaces the legacy USB Type-B connector with a modern USB-C interface for a stronger, more reliable connection and simplified plug-and-play integration.

Lightweight & Rigid
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CNC-machined aluminum alloy body provides a lightweight yet rigid structure.
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Internal filter carousel is crafted from 6061 aluminum alloy, reducing weight while maintaining excellent strength and stability.
The result is a compact, durable design engineered for smooth and 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 motorized, bidirectional filter-wheel drive features precise position indexing.
When controlled through software such as ASIAIR (sold separately), it enables automatic filter changes during scheduled imaging sessions – allowing fully unattended, hands-free astrophotography.

Connection
- ZWO EFW-5×1.25-25
- ZWO EFW-8×1.25-25

Diagram

What`s in the box?

- EFW Body
- 1.25" Cover
- 1.25" Holder
- M42M-M42M Adapter
- 1.25" T Nosepiece
- M2.5*6 Screws (6 pcs/bag)
- M2*4 Screws (26 pcs/bag)
- M4*12 Screws (2 pcs/bag)
- 3 X 75mm Phillips Screwdriver
- 1.25" Bracket
- USB 2.0 Cable (2m x 1)
- A Bag of Filter Masks (10 pcs/bag)
- USB 2.0 Cable (0.5m x 1)