Your small, hometown-attitude company Keith Specialty Store 6791 Rt 119 Hwy N, Marion Center, PA 15759 US callers: 800-705-8838 FAX: 724-397-2228 Outside the US: 724-397-8838 8:00am-6:00pm M-F, 8:00am-3:00pm Sat. (ET)
Sometimes called wall stack, these parts are used for running duct inside 2″x 4″ and 2″x 6″ walls or for use as low profile duct inside stud cavities. Wall stack is rectangular and comes in two thickness. Oval pipe is also used inside walls.