Many older homes, especially in the north, have gravity heating systems that have large, triangular baseboard registers that have become hard to find. Finally we have a solution for these homes. The Madelyn Carter Vintage Baseboard Registers are available in 2 Sizes: 15" x 12" and 13" x 12", 2.5" deep at the base and 1" at the top. Comes in two pieces (sold as one unit) a baseboard frame and register insert (with damper). Simply mount the frame to your wall using the provided 3" screws and then install the insert with damper using the two 1/2" screws.