1-5/8" x 50' Roll, Butyl Deck Flash Barrier, Prevents Wood Rot Created By Moisture By Sealing Around Deck Screws, Nails & Metal Flashing & Hangers, Can Be Applied To Wet & Damp Wood & Temperatures Down To 25 Degrees, Self Adhesion, Apply To Top Of Floor Joist & Around Flashing Areas Where Metal Joist Hanger Will Be Applied.