Selkirk RV Adjustable Round Gas Vent Pipe is designed to be used alongside a straight length vent pipe, ensuring that the exact required vent length can be achieved with ease. This component allows for simple disassembly and effectively absorbs the linear expansion that occurs in longer pipe lengths. Available in two adjustable sizes, the 12-inch length adjusts from 3-1/2 inches to 10-1/2 inches, while the 18-inch length adjusts from 6 inches to 16 inches. The size refers to the inside diameter of the pipe or fitting, with the outside diameter of the RV vent being approximately half an inch larger. Constructed with an aluminum liner and galvanized steel jacket, this Type B gas vent is rated for temperatures up to 550 degrees Fahrenheit and is UL Listed for safety and reliability. It comes in various sizes ranging from 3 inches to 6 inches in diameter and packaged individually. This vent pipe is an i solution for accommodating precise vent lengths and managing thermal expansion in gas venting systems.