This brass harp will sit onto a standard ES | E27 | Edison Screw lampholder as it has a 40mm hole.
The top has a 10mm hole.
The concept of this style of harp is if you have a glass shade with a hole in the top you will place this over the harp, then get a pottery nipple (86986) and push it from inside the harp and out the top of your shade.
Once this is done you may need a sconce to sit on top (5507718) then followed by a finial to hold the installation into position.
Note: the pottery nipple may or may not be long enough so a different way of fixing may be required please contact us if you need help.
Fixing Hole: 40mm
Top Hole: 10mm