Fits a roof pitch of 15&8211;90 degrees, PEFC-certified timber, sourced from well-managed forests, VELUX roof windows are best weatherproofed using VELUX window flashings, VELUX patented corner brackets ensure fast & secure installation, Ventilation flap can be operated with the window closed, Protective clear lacquer, Wide range of glazing options available, Forest friendly timber frame, High quality natural pine