madelyn carter 6" x 12" cathedral floor and wall registers, cast aluminum (overall size: 7-1/2" x 13-1/2") madelyn carter the madelyn carter vent covers unlimited family has crafted long-lasting decorative registers & returns for over 15 years. we are a family-owned and operated company that strives to bring top-notch quality, unsurpassed selection, and a first-class customer experience to everyone of our customers. whether you are building new, remodeling, or just want to upgrade the details of your home or business, we are happy to help. be sure to choose the correct dimensions before checking out. unsure what model you need? it’s easy to find the correct size for your wall, ceiling, and floor vent covers. first, remove your existing register. measure the size of the duct opening. most importantly, order by the size of the duct. do not order by the size of your existing vent cover.