Insulates around the roof window frame, reducing heat loss and eliminating cold bridges. Makes insulating and installing the roof window a simpler process. Supplied with BFX underfelt collar and transverse drainage gutter. Click fittings ensure fast and a
Insulates around the roof window frame, reducing heat loss and eliminating cold bridges between the window and roof structure and comes with a Velux BFX underfelt collar and transverse drainage gutter