Our Telescopic Letterbox Insert Flange is designed to frame and brace our 240mm and 340mm telescopic letterbox inserts. It makes installation faster, hides brickwork imperfections, and gives the rear opening of your letterbox a clean, professional look. Fabricated from aluminium and locally powder-coated, it’s built to withstand harsh outdoor conditions without rusting — unlike galvanised alternatives.

For 340mm Telescopic Insert Letterboxes:

• External Size: 400mm (W) x 220mm (H)

• Internal Size: 355mm (W) x 175mm (H)

• Flange/Lip Width: 25mm around the perimeter

• Tab Depth (Insert into wall): 90mm

• Fits Insert Size: 340mm (W) x 165mm (H)

For 240mm Telescopic Insert Letterboxes:

• External Size: 300mm (W) x 220mm (H)

• Internal Size: 255mm (W) x 175mm (H)

• Flange/Lip Width: 25mm around the perimeter

• Tab Depth (Insert into wall): 90mm

• Fits Insert Size: 240mm (W) x 165mm (H)

Material & Finish:

• Aluminium construction

• Locally powder-coated for durability

• Rust-proof and weather-resistant

• Creates a neat, framed look at the rear opening

• Covers imperfections and gaps in brickwork

• Makes install quicker and more secure

• Internal tabs slot easily into wall cavity

• Compatible with 240mm and 340mm telescopic inserts

• Rust-free alternative to galvanised frames