This Poly Foam Caulk Saver is ideal for various projects around the home. Simply press it into place to fill in large gaps and work right over it. This 1/2" x 20' Caulk Saver is moisture-repellent and very durable. It also works with virtually any kind of sealant. Key Features Include: -Made from durable poly foam -Reduces the amount of caulk needed for large gaps -Frost King Caulk Saver works with virtually every type of caulk and sealant -Moisture-repellent and resilient -Press into place and caulk on top