VP4-48STR Noritz Stainless Steel 4" Diameter / 48" Straight Single Wall Venting Pipe  The VP4-48STR is a clean and durable stainless steel single wall venting pipe. This 4 " diameter straight component is part of the N-Vent system, meaning its components form a perfect seal without the need to tighten. A quick-snap feature allows for easy connections making installation of a professional grade system easier than you would think.High temperature rated stainless steelEasy to install Quick-snap connectionUnique gasket enables tight sealSuperior design enables professional installation