AutoLEDTech.com 's Butyl Rubber Headlight Sealant is the perfect product for sealing up your custom headlight retrofit builds and installs! Easily seal and protect against moisture ingress with the Rubberwerkz Butyl on any headlamp or tail lamp that has the sealant channels in good shape (DOES NOT WORK WITH HEADLIGHTS THAT ARE CUT OPEN!) This sealant was specifically designed to seal headlamps with a firmer composition than an auto-store butyl windshield glue. This gives an easy-to-work-with application.