Siroflex. Suitable for sealing around siding, windows, and doors, Duo-Sil low-VOC caulk is available in 115 in-stock colors. The urethane emulsion sealant bonds to most substrates, including wood, metal, concrete, gypsum, and more. The high-gloss finish ensures a professional look, and the material will not shrink or crack over time, the maker says. Also suitable for interior projects, such as countertops or moldings. 800.359.6398