Universal table clamp / lamp bracket that should fit any standard table top (approx. 26-38 mm). All you need is a standard 40+mm M6 hex screw + nut. The screw and nut are not included.
I have included an adapter (Part C) that I use for my own lamp designs. However, you can attach pretty much anything to the back of the clamp with 4 M3 screws (spacing 17.5 x 20mm) or to the adapter with two M5 screws (spacing 20mm).
Enjoy!