Suction cups offer a temporary solid light mounting solution on smooth nonporous surfaces. They are great for mounting small lights; cameras and accessories to windows, mirrors, automobiles, boats and any other smooth nonporous surfaces. Because of the excellent rubber material with silicon, Kupo suction cups can be used at temperatures from -12 degrees to 49 degrees c. / 10 degrees f to - 120 degrees f. A red-line indicator is equipped in most suction cups warning of any vacuum loss due to adverse shooting conditions. This 6" pumping suction cup comes witha swiveling adapter which is detachable. Both ends of adapter come witha ball joint 5/8" (16mm stud ); tapped for 3/8" and 1/4" and a pad protector max. Loading: 4.5 kg (9 lbs) weight:0.7 kg ( 1.54 lbs)