Filter Retaining Masks for ZWO EFW 2" (SKU: ZWO EFW-2-MASKS) is a set of 10 masks designed to secure round 50 mm unmounted filters in ZWO EFW 5 × 2" and EFW 7 × 2" electronic filter wheels. The ring-shaped design holds the filter around its edge, leaving a clear aperture of 48 mm.

Each mask has three mounting holes and attaches to the filter wheel carousel using the included M2 × 4 screws. The set can be used to replace worn or missing retaining components. The manufacturer confirms compatibility with both the earlier EFW 5 × 2" and EFW 7 × 2" filter wheels and the EFW-5x2-25 and EFW-7x2-25 models introduced in 2025.

Key features

• secures round 50 mm unmounted filters
• compatible with ZWO EFW 5 × 2" and EFW 7 × 2" filter wheels, including the 2025 versions
• 48 mm clear aperture
• three mounting points on each mask
• set of 10 masks with mounting screws

Included items

• ZWO EFW 2" filter retaining masks – 10 pieces
• M2 × 4 Phillips flat-head screws – 1 set

Technical specifications

• manufacturer: ZWO
• model designation: EFW-2-MASKS
• compatible filter wheels: ZWO EFW-5x2, EFW-7x2, EFW-5x2-25, EFW-7x2-25
• supported filters: round, 50 mm, unmounted
• mask clear aperture: 48 mm
• number of mounting holes per mask: 3
• mounting hole diameter: 2.1 mm
• mounting screws: M2 × 4
• mask colour: black
• number of masks included: 10