SILA-SEAL Professional Grade Silicone Sealants are a one-part, non-slumping RTV. This black silicone cures upon contact with moisture in the air and mostly used for general purpose sealing. SILA-SEAL Professional Grade Silicones cure to a tough, rubbery solid, and provide long-term flexibility and durability. Ideal for heating and air conditioning (HVAC), plumbing, construction, and other general purpose applications. SILA-SEAL Professional Grade Silicone Sealants are perfect for the DIY bathroom remodel or the professional kitchen renovation, and everything in between.