This background clamps set from studioking consists of two clamps of 15cm. the clamp is practical for attaching various studio accessories. for example, the clamp prevents unwanted unwinding of your background paper. the background clamp weighs only 98 grams (each) and has the dimensions 158 x 120 x 23 mm. the clamp can be opened up to +/- 60mm. Usage studioking background clamp 2 pcs. 15 cm You can us this clamp to fix background boards, background paper, background cloths, reflectors etc. to a tripod or rod. when using it with a background paper roll, the clamp needs to be mounted on the side and not on the background roll itself. this prevents damages on the rol.