Apply heat and these grommets shrink around wire, cable, and cords to keep out dust, debris, and moisture. A rubber adhesive on the inside makes the bond extra secure, while the flange covers imperfect holes. Made of plastic, these grommets are chemical resistant. They won't dry out and become brittle when exposed to UV rays. All have an extra-hard rating to withstand high levels of impact. They can also be used outdoors.