The VELUX BFX 1000 underfelt collar is a pleated material that ensures a flexible and tight seal to the underfelt of the roof, whatever it's construction. It also comes with a transverse drainage gutter that helps lead water away from the head of the roof window if a tile or slate is broken above the window.
✓ Made from diffusion open material to minimise risk of condensation
✓ Welded corners ensure a watertight and simple installation
This product does not need to be purchased if you have the BDX 2000 in your basket, as it is included in the BDX 2000 package.