Test Balls are made to order.
Our Test Balls are available with a ball bearing size ranging from 0.5mm - 10.0mm diameter. Other Ball Bearing Diameters available on request. It is designed to be used on 'Conveyor' or 'Drop-Through' metal detector systems. 
Dimensions (Approx): 35mm Diameter (38mm Spherical Diameter) x 35mm High