The Velux BFX 1000 Underfelt Collar offers a strong connection between the roof window and membrane. It helps reduce harsh weather penetration and cold air from entering your property.
It is supplied in one piece ensuring it is easily installed around windows, corners and frames.
Includes a drainage gutter which will lead water away from the top of the window if there is any broken roof material above it.
It will help maintain your property and ensure a professional finish.