Dedolight - 152 mm (Approx. 6 Inch) diameter vacuum cup creates a powerful suction, enabling you to mount the dedolight head securely to windows, doors or other flat, nonporous surfaces. The swivel joint has a 16?mm (Approx. 5/8? Inch?) stud for easy mounting of light fixtures up to 15 kg (Approx. 33 lbs).