Also known as neutral cure, this sealant won't discolor copper, brass, and concrete. It is a structural sealant that combines the mechanical strength of an adhesive with excellent sealing properties and high flexibility. It’s non-sagging, so it won't drip from vertical and overhead surfaces. Made from silicone, this sealant is RTV (room-temperature vulcanizing).

Elongation and joint compression/expansion tolerance indicate flexibility—the higher the values are, the more joint movement a sealant can sustain. This sealant is best suited to joints between similar materials that aren't exposed to wide temperature fluctuation.