Vacuum cups employ the force of atmospheric pressure to grip a surface: When a vacuum exists between the cup and the surface on which it is attached, the weight of Earth's atmosphere holds the cup in place with incredible force. Unlike suction cups that produce a vacuum as they pull away from the surface, Powr-Grip® vacuum cups use a hand-actuated pump to efficiently remove air from between the rubber pad and the attaching surface--thus creating a much more reliable hold. Because the full face of the pad is brought into contact with the surface, distortion is reduced, allowing the cup to be used on materials of almost any thickness with little risk of damage.

The vacuum cup's pump features a plunger with a red line, which serves as a vacuum indicator. Introduced by Wood's Powr-Grip in the 1960's, this safety device is still recognized as one of the most reliable warning systems available. A few strokes of the plunger evacuate the vacuum pad, causing it to seal securely to the attaching surface. When the cup is attached completely, the plunger stops moving and the red line is hidden within the pump. A visible red line indicates that air has leaked back into the pad, making vacuum insufficient to use the cup. However, if the red line becomes visible while the cup is in use, a check valve allows the user to repump the cup without losing the remaining vacuum.   CLICK HERE to view a 360 degree rotating image.

Lifting on the release tab near the edge of the pad allows air to refill the evacuated space, so that the vacuum cup detaches completely.