Vent Termination Kits 3" - Vent Termination Kits 3" improves efficiency furnaceVent Termination Kits 3" features include:Concentric vents make it eaiser to have a two pipe installtion for high efficiency furnacesThese vents simplify installation and only require one hole through the wall or roof where the pipes terminateWithout using these vents, the installation would require cutting two holes through the home - one for each pipeThese vents save time and money by reducing the amount of work requiredConform to ANSI/ASTM StandardsOrder Qty of 1 = 1 ventBelow is more info on our Vent Termination Kits 3":