The Howdy Home Telephone Super D allowed up to eight telephone sets to be connected using two telephone lines. This model had a rich set of extension features, getting the full benefit of the capability of accommodating two lines. For example, when used in a building used as both a residence and a store or in a house designed for two generations to live independently of each other, the Howdy Home Telephone Super D allowed each side to keep privacy and to transfer calls between the two. The telephone set had also a single-touch dialing feature for 10 numbers. The body color was selectable between two colors (ivory white and pale green).