The Cromar Vent3 Pro Roof Underlay is a high-performing, breathable roof membrane designed to protect your home from the elements. This 50 x 1.50m green underlay is manufactured by Cromar, a brand synonymous with quality in the roofing industry. Made from a triple layer fabric, it provides excellent strength, durability and water resistance. Its an ideal choice for both cold and warm roof applications, ensuring optimum ventilation and protection against wind-driven rain, snow and dust.