The FB214 14 25 Silver Double Ply Black Poly R-4.2 from Mueller Streamline is a high-quality insulation product designed for optimal thermal performance. This double ply construction ensures durability and resistance to wear, making it suitable for various applications. With a thickness of R-4.2, it provides excellent insulation properties, helping to maintain temperature control in piping systems. The black poly finish adds an extra layer of protection against environmental factors. Ideal for both residential and commercial use, this insulation product is essential for energy efficiency.