Plastic fan backdraught shutter non return check valve for better ventilation purpose prevent insects and smoke

Features: 

1. Made of ABS plastic, which is antistatic and ageing resistant. It can keep away distortion for a long time.

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.

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