Does your roof still have felt underlayment? Are you ready to improve your roof and step into modern roofing technology. Rhino U20 is a synthetic underlayment which is competively priced with the inferior product felt. Did you know that felt will actually start to hold water and deteriorate? You will not have to worry about that with Rhino U20 because has soon as Rhino is attached to your roof your roof becomes water tight and the water slides right off. The synthetic material has a second layer which allow extra protection and is 8 times stronger than felt! Come upgrade your underlayment with the Rhino strong product.