J305 Geiger Muller Tube Counter Glass Tube Hard Beta GM Detectors Geiger Counter Tube The Tube for Nuclear Radiation Detector. Feature: Comprehensive Radiation Detection, High-Sensitivity Geiger Counter Tube, Versatile GM Tube Applications, Complete Geiger Counter Kit, User-Friendly Geiger Kit. Specification: Origin Mainland China, Application temperature -40°C~55°C, Can be used for Gammaray 20mR/h~120mR/h, Betaray range is 100~1800 Changing index/minute.CM2 softBetaray, Working voltage 380-450V, Working current 0015-0.02mA, Sensitivity to gamma radiation 0.1 MeV, Self background 0.2 pulse/second, Length 107±5mm, Diameter 10±0.5mm, Material Glass, Product size 107.00x10.00x10.00mm, Product size 4.21x0.39x0.39inch