A permanently open vent with visible airflow marking to comply with the requirements of BS5440 Part 2 2000 : BS EN 13141-1:2004.
Simple screw fixing.
Excellent airflow properties
-Manufactured by injection moulding ABS/HIPS.
-Durable and totally resistant to decay.
-Manufactured in the UK to BS EN IS0 9001 and BS EN IS0 14001.