The ZWO EFW Mini 5 × 1.25" / 31 mm (2025 version) is a compact, lightweight electronic filter wheel designed for astrophotography setups where minimal weight and short backfocus are essential. The redesigned 2025 structure improves light-blocking performance through enhanced sealing, refined mechanical tolerances, and a fully enclosed motor chamber. The wheel accommodates five 1.25" filters or — alternatively — five **31 mm unmounted** round filters. With an optical thickness of 20 mm and a total weight of just 300 g, it is ideal for small imaging systems and portable wide-field rigs.

Key features

• compact Mini version — optimized for lightweight imaging configurations
• upgraded 2025 anti light-leak structural design
• 5 filter positions for 1.25" or 31 mm unmounted filters
• optical thickness: 20 mm
• weight: 300 g
• USB-C port for both power and communication (120 mA @ 5 V)
• high-precision stepper motor for stable and accurate indexing
• CNC-machined aluminum body; 6061 aluminum filter carousel
• fully compatible with ZWO 1.25" and 31 mm unmounted filters
• works with ASIAIR, ASIStudio, ASCOM and the ZWO SDK
• true plug-and-play operation – no drivers required

Included items

• ZWO EFW Mini 5 × 1.25" / 31 mm (2025 version)
• 5-position filter carousel
• USB-A → USB-C cable
• filter mounting screws
• hex key
• user manual

Technical specifications

• model: ZWO EFW Mini 5 × 1.25" / 31 mm (2025)
• number of slots: 5
• compatible filters: 1.25" and 31 mm unmounted
• optical thickness: 20 mm
• weight: 300 g
• power: 5 V via USB-C (120 mA)
• interface: USB-C
• body material: CNC-machined aluminum
• carousel material: 6061 aluminum
• motor: high-precision stepper motor
• anti light-leak design: improved sealing + enclosed motor housing
• software compatibility: ASIAIR / ASIStudio / ASCOM / ZWO SDK
• drivers required: none (plug-and-play)