Designed for our Premium 1/2" Square Staffs the "add on" hangers below either clip on - or attach with a simple twist motion. No tools required! All three attach to any 1/2" Diameter round, and 1/2" Square staff or deck hangers. The upper hook (FPAR2) has the distinct advantage of also attaching to the following: RT2CL RT2D RT2CLV and either of our Balluster Hangers