Filter Retaining Masks for ZWO EFW 7 × 36 mm (SKU: ZWO EFW-7-MASKS) are a set of 10 masks designed to secure round 36 mm unmounted filters in ZWO electronic filter wheels. The masks hold the filters around their edges, leaving a clear aperture of 34 mm.

The set is compatible with the ZWO EFW-7x36 and EFW-7x36-II seven-position filter wheels and the EFW-7x36-25 model introduced in 2025. Each mask has three mounting holes and attaches to the filter wheel carousel using the included M2 × 4 screws. The set allows worn or missing retaining components to be replaced.

Key features

• secures round 36 mm unmounted filters
• compatible with ZWO EFW-7x36, EFW-7x36-II and EFW-7x36-25 filter wheels
• 34 mm clear aperture
• 0.5 mm mask thickness and three mounting points
• set of 10 masks with mounting screws

Included items

• ZWO EFW-7-MASKS filter retaining masks – 10 pieces
• M2 × 4 Phillips flat-head screws – 1 set

Technical specifications

• manufacturer: ZWO
• model designation: EFW-7-MASKS
• compatible filter wheels: ZWO EFW-7x36, EFW-7x36-II, EFW-7x36-25
• supported filters: round, 36 mm, unmounted
• mask clear aperture: 34 mm
• mask thickness: 0.5 mm
• number of mounting holes per mask: 3
• mounting hole diameter: 2.3 mm
• mounting screws: M2 × 4
• mask colour: black
• number of masks included: 10