GTMat 10 sqft Logo Onyx (12" x 12" Sheets) 70mil Butyl Truck Audio Car Sound Deadener GTMAT ONYX 10 sqft Automotive Sound Dampening Real True Butyl - Noise Deadener Installation Kit Includes: 10 x 1sqft logo'd Sheets (12 x 12), Instruction Sheet, GT MAT Decals This item is 100% all butyl with 70mil of thickness and a temperature rating of up to 400 degrees Fahrenheit.