This is for 5/10 adapter Rings which will convert a 46mm continental-size fitting to a 29mm British standard size lamp holder. Suitable for use either in-ceiling pendants or may be placed above and below lampshade. Which is used on a table lamp to give more stability. Made of metal/Plastic. It is more durable than others in that it will not crack melt or distort with heat. Please Select the Desired Quantity from the drop-down bar. Converts European and Continental lamp shades to British lamp holder size, and this lampshade reducing ring can work for round head bulbs of various types, helping to fit different lamp holder sizes.