Hangzhou Dongxing Telecommunication Material Co.,Ltd is one of the professional China air conditioning aluminum foil flexible duct manufacturers and suppliers, and equipped with a productive air conditioning aluminum foil flexible duct factory and company, welcome to contact us.Product Details    Key Specifications/Special Features:Product Description1/2 layer(s) of aluminum foil polyester duct, supported by spring wire. Total 3 layers:1st layer: Aluminum foil (32um raw material)2nd layer: Polyester (13um)3rd layer: Aluminum foil(Additional layer of 2 layers duct)Spring wire: carbon steel from 0.9~1.3mmTechnical specification:1. Air velocity: 30m/s (max)2. Temperature range:-30