Holder for Geiger-Muller Tube.A square metal body 50mm x 40mm (length x depth) which houses the tube socket and is mounted on a 100mm long sheet metal plate with rubber feet. A captive co-axial connecting lead 1M long is provided, terminating in a standard BNC connector. A 2.2 MΩ protective stabilising resistor is internally wired in series with the anode connection. Maximum input voltage:500V DC. Geiger-Muller Tube is not included, but can be purchased separately (B8A49724)