Temperature extremes are no match for HM270 - an acetoxy silicone that withstands harsh conditions from -76°F to 350°F without missing a beat. Designed for use on non-porous materials, its application possibilities include a variety of tough challenges: ceiling skylights, solar panels, duct work, aluminum siding, recreational vehicles and more. With 25% joint movement, it’s also permanently flexible. HM270 should not be painted