Closed cell Neoprene sponge cord is an ideal sealing material for a wide range of applications around the home and in every industry. Precision formed with a 100% closed cell rubber, which does not absorb nor allow the passage of fluids or air. The Herco brand neoprene sponge rubber cord has excellent compression characteristics that are ideal for sealing gaps or voids. It provides long-term performance in indoor or outdoor environments.