The HydroShield 25 Synthetic Underlayment Samples are a 10 in. x 8 in. cut piece of the Hydroshield 25. Hydroshield 25 underlayment consists of 100% synthetic woven material with a cool grey spunbond non-woven fabric walking surface, and it has high tear strengths and a slip-resistant, non-woven backing made of Aqua Trak. It is UV resistant and can remain uncovered for up to 6 months. This underlayment has a 25-year warranty and is guaranteed to shed water. A pre-printed nailing pattern and overlap lines speed installation.