"Tough, flexible cavity sleeves and baffle and extension accessories, to provide ventilation through external walls to the building interior. Suits a single 9”x 3” Timloc airbrick and provides a maximum equivalent area of 6170mm2. Injection moulded in polypropylene Unrestricted free airflow Lightweight and easy to handle Durable and totally resistant to decay Satisfies all NHBC requirements Manufactured to BS EN ISO 9001 and BS EN ISO 14001 Complies with all relevant Building Regulations Meets all relevant British Standards"