These replacement clamps are for photographic lighting stands, The original ones fracture on the stands bought on Ebay. I have replaced mine with these 3d printed ones.
Best if printed vertically, I manged to print mine without any support, however they do need a bit of cleaning up afterwards.
light_clamp_23.stl | 205.0KB | |
light_stand_clamp_20mm.stl | 1.4MB |