ABS MATERIAL ：Extractor fan accessories made of ABS material material, non-toxic and tasteless，can be used long time ANTI-RETURN WIND ：Back draft damper designed to provide anti back draught, and fit in between solid plastic ducting, flexible ducting. CLOSED WITH ：The rear ventilation baffle is closed by gravity, integrally formed to seal and leak-proof, and light in weight, suitable for 4-inch pipes and can prevent cold air from backflow SPECIFICATION SIZE:Material: ABS plastic,caliber: approx. 95mm / 3.7in,width: approx. 80mm / 3.1in,height: approx. 118mm / 4.6in WIDELY APPLICATION:Draught fan light weight, suitable for 4in pipelines,Suitable for kitchen, toilet, bathroom, etc., Manufacturer: Oumefar