Caulk Saver helps insulate and cushion while reducing the amount of caulk needed to fill or seal large openings Use to back fill large gaps before applying caulk (caulk sold separately) Helps insulate and cushion while reducing the amount of caulk needed to fill or seal large openings Suitable for use with pavement, cracks, wall joints and foundations Compatible with most caulks and sealants Made of resilient, closed-cell poly foam for durability