J.W. Winco 51.7-ND-43-A Retaining Magnet, Ball Knob Rubber Jacket, GN51.7, 10.69" Diameter, 0.22" Thickness, Steel Zinc Plated Housing, Neodymium/Iron and Boron NdFeB Magnet, Elastomer Rubber Jacket (TPE), 73 Shore, Technopolymer Plastic Ball Knob, Matte Black