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Soft-PVC, transparent, colourless Suction Cups, with transverse hole, stick to every smooth surfaces like glass, glossy tiles or varnished wood.
A nylon filament or any kind of thread can be pulled through the transverse hole in the sucker itself in order, for example, to hang decorations on window, wall or car windscreen.

In order to obtain a good amount of adhesive strength, both the intended surface and the suction cup should be cleaned with a glass cleaner to remove any grease or other impurities. The sucker should be pressed into place after the surface and cup itselves are clean and dry.
Contrary to the supposed common knowledge, suction cups should NOT be applied when wet.
When correctly applied, the suction of the cups should hold for 4 – 5 years. Although the soft-PVC will begin as early as two years to turn yellow, this will not compromise their adhesive strength.

Also interesting: the most efficient retention force proportionate to size is found with the suction cups with a diameter of 40 mm. If the air remaining under a suction cup expands as a result of, for example, being heated, the smaller suction cups will lift off of the surface. In the case of the 40 mm suction cups, however, their surface area is large enough that the suction will hold. This is especially noteworthy in the case of display windows and windscreens which are exposed to a great many temperature swings.

Package includes 3 suction cups with a diameter of 40.0 mm and a transverse hole (hole diameter is 3.5 mm)