VELUX Underfelt Collar and Transverse Drainage Gutter ensures a weathertight seal between the roof window and the roof. Pleated material ensures a flexible and tight seal to the underfelt of the roof, whatever its construction. Comes complete with transverse drainage gutter to lead water away from the head of the window if a tile or slate is damaged above the roof window. Welded corners ensure a watertight and simple. Available in a range of sizes.
