The Lochinvar & A.O. Smith 100284322 Venturi Natural Gas Assembly is a replacement component designed to regulate and mix natural gas with combustion air in compatible boilers and water heaters. Its Venturi design helps create the proper gas-to-air mixture for efficient and stable burner operation. Used in select Lochinvar and A.O. Smith heating equipment, this assembly supports consi... https://www.partshnc.com/lochinvar-a-o-smith-100284322-venturi-assembly-for-natural-gas-nk-150