MuteX Soundproof Material (Black, 30 sqft, 5'x6') MuteX is made in the USA and has an STC rating of 32. Compact & Lightweight at only 1/4" thick and 1/4 lb/sqft 2 Stage Sound Barrier using Polymute Resin + Carbonweave All Weather Tempature Range from -50F degrees to 350F Used in Automotive, Industrial, Commercial, Home Construction for HVAC, Walls, Floors, Ceilings, Doors, Condominiums, Motors, Trunks, Speaker Boxes, Recording Studios, Curtains, etc.