Bufftech T15 Concave Posts are designed to fit the Danbury Concave and Rothbury Concave Fence Styles. These posts are pre-routed to accept the rails of the fence sections. Line posts are routed so that you can create a straight line of fencing. Corner posts are routed so that you can create a 90 degree corner. End posts are routed on only one side so that you can terminate your fence line, or hang a gate.