The Prowood 1-5/8 In. X 50 Ft. Black Butyl Deck Joist Tape is designed specifically for use under decking boards to provide a secure and stable foundation for your deck. This deck tape model, featuring a black butyl material, is durable and reliable for long-lasting performance. The 50-foot length ensures that you have plenty of tape to cover your deck joists effectively, while the brand's reputation for quality craftsmanship ensures that your deck will be supported well for years to come.