This Shade Carrier (3 inch)will fit onto any Irish, British (BC) or (E27) European lamp holder fittings.What is a shade carrier?It's used to connect lampshades manufactured with Duplex rings to lamp holders and control the height between.How to useThis shade carrier will fit into a lampshade that is equipped with a standard Duplex ringThe internal diameter of a standard duplex ring measures 107mm. One end fits onto the lamp holder, and the other end is cradled to hold the duplex ring of the Lampshade. The lampshade is then placed on top. What type of lamp holders will this Shade Carrier fit?The frame is manufactured to fit European lamp holders, and a Converter/Reducer Adaptor plug is supplied to reduce the apertureso it can fit Irish/UK lamp holders. Lampholder TypesB22 Bayonet Cap Lampholders (Ireland/UK) - Adaptor FittedE14 Edison Screw Lampholders (EU) Adaptor FittedE27 Edison Screw Lampholders (EU) Adaptor RemovedE26 Edison Screw Lampholders (US) Adaptor Removed What's included?1 x 3" Inch (7.5cm) High Shade Carrier1 x E27/E26 to B22/E14 Lampshade Reducer / Converter AdapterSpecifications4mm top quality heavy gauge wireEpoxy coated /painted white (prevents rust)