150mm Extractor Fan Backdraught Shutter , back draught shutter

Features: 

1. Made of stainless steel.

2. The outlet sizes choice : 100mm, 125mm, 150mm, 200mm, etc.

Benefits to set this product to the ventilation pipe:  

prevent outside air from penetrating the home.

prevent the smoke from public pipe enter into the home.

prevent insects fly or climb into the ventilation pipe.