Max Strength Silicone .25" Medium Gap Weatherstrip Seal White, 2 Strips - Even small cracks and gaps around windows and doors can cause drafts that lead to high energy costs. Duck Brand Max Strength Silicone Weatherstrip Seals are used to seal smaller gaps up to 1/4 in. around windows and doors that may let outdoor air inside. They can also help keep out unwanted dust, insects and pollen during the warmer months. Designed with silicone, these self-adhesive seals come with a lifetime guarantee and won't crack or split over time. Simply separate the dual strip into two pieces, cut to size and then apply to your window or door for added weather protection.