This is a set of two black Triple Background Hooks with Two Superclamps from Impact. This system allows you to hang up to three rolls of seamless on your optional background support system. The two Superclamps attach to the uprights of the support system and two Triple Hooks attach to the Superclamps using the included hardware. Superclamp: Weight: 0.9 lb (0.4 kg), Maximum load capacity: 33 lb (15 kg), Fits tubes: 0.51 to 2.16" (1.3 to 5.5 cm)