Easy to install, screws onto the lamp harp after the lamp shade. Lamp finials are threaded to fit standard lamp harps Secures lampshade to standard table or floor lamps Antique brass decorative metal lamp part shade finial of an ANCHOR that measures 1 5/8" wide x 3 1/2" tall. It has standard threaded finial hole (1/4-27) that works with standard harp (lamp bracket). Please note- this will only work with a lamp shade harp (bracket)- if you need this to work with lamp pipe (standard 3/8" outside diameter) then you will need to buy a reducer. Like Amazon item #B07D7H2P76.