A multipurpose GM tube, sensitive to alpha, beta and gamma radiation. Mounted in housing with protective cover and 10 mm diameter support rod. It is complete with integral lead and BNC connector. This GM tube does NOT have built-in anode resistor, and therefore requires counter with built-in anode resistor. Suitable for use with Code 80705 Geiger Muller Counter - Frederiksen. Window diameter: 9.14 mm Recommended bias voltage: 500V BNC plug