gas mask 1. silica gel material, 2. with activated carbon cartridge, 3.A.K.E cartridge,light weight, 4.ISO 9000, Respirator mask (9001) 1. head hoop suspension, it is more comfortable to wear. 2. good quality silica gel 3. with activated carbon cartridge, the unique design is well received 4. airtight mattress help improving efficiency 5. cartridge uses light and handy, enviroment-friendly ...