The CRL 5" Heavy-Duty Triple Vacuum Cup gives you a more positive grip on your glass. This heavy-duty vacuum cup has the industry-proven design that has been a favorite of the glass industry for decades. The third 5" (127 mm) cup gives added grip, which enables the glass setter to maneuver the glass without changing the position of the cups. They are made of the same sturdy material and same size rubber as the double cup models. Their cast frames have a smooth yet durable finish that resists corrosion and the abuse that comes from everyday use. Its rubber pads get a good grip on glass, marble, granite or any smooth surface material. These are a practical and affordable material handling system that will give you years of good service. They are quality made by CRL in the U.S.A.