Manually Operated Hand Vacuum Cups - Single HandcupHand vacuum cups are designed to handle smooth, nonporous loads such as metal, glass, plastic etc. more effectively and more efficiently. These cups make the task of lifting much easier by allowing less awkward lift points and eliminating pinched fingers. Very easy to use the lever grip is squeezed together on the cam levers are flipped into position and then rubber pads are securely clamped to surface by vacuum. Just flip back lever(s) to release.