This is s an easy to print nice lamp called : Clothilde.

It is a multi-wall spiralized lamp (yep it is possible)

This is the original one, others you see are copies of this design from 2019.

No screw, no tools needed and of course no support

The internal dimension of the lampshade is 40mm (or 1 9/16 inch). Ideal for a E27 mounting bracket.

(I'll give in this file some variations of internal size to fit any socket)

Diameter 250mm
Height 250mm

(Ok bambulab)

If you need a variation of this shape for another dimensions send me a message.