Manufacturer Name: Lochinvar & A.O. Smith Product Number: 100111100 OEM Part Number: 100111100 The Lochinvar & A.O. Smith 100111100 3 Inch Concentric Vent Kit is designed for efficient venting of gas water heaters and boilers. This kit features a compact, dual-wall design that allows for both intake and exhaust through a single opening, simplifying installation and improving aest... https://www.partshnc.com/3-concentric-vent-kit-4