British Made Lampholder SES / E14 10mm Threaded Entry, Shade Compatible (Lock Rings Included)
Width: 31mm, Height: 57mm
If this lampholder was a car it would be an Aston Martin or Bentley. Arguably over specified, it is machined and milled to perfection. If the lampholder is visible this model will tick all the boxes. Fits a 30mm shade hole.
If in doubt consult a qualified electrician