These Heavy-Duty CRL Vacuum Cups have the industry-proven design that has been a favorite of the glass industry for decades. Their cast frames have a smooth yet durable finish that resists corrosion and the abuse that comes from everyday use. The large 5″ (127 mm) diameter 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.