Techno SB50 is a 100% synthetic woven roof underlayment offering high tear strengths, including a tacky back-side slip resistant coating for added walking traction and a cool grey spunbond non-woven fabric surface. Aqua Trak system. UV resistant and can be left exposed for up to 6 months. 50 year warranty - guaranteed to shed water. Pre-printed nailing pattern and overlap lines speeds installation.