Features: 1Applicable: This DIY opening source Geiger counter kit is compatible for radiation detector, please confirm the detector model before use. 2Purpose: Nuclear radiation detection, for detecting 20mR/h?120mR/h gamma rays and 100?1800 off variables per points of the soft beta ray. 3Sound and Light Alarm: This DIY detector has a sound and light alarm function, which will alarm in time when detecting abnormal data. 4GM Tube: The tube is a tin oxide cathode, coaxial cylindrical thin wall structure (pipe wall density 5010cg/cm2), pulse applied halogen pipe. 5Suggestion: Please remember that building materials may contain natural radionuclides, which is why you should be careful to choose materials when building, because they will pose a great threat to your health, when moving to a new place, you must check there is no radiation. Item Type: DIY Geiger Counter Kit Material: Circuit Board Gross Weight: 168g / 5.9oz Product Size: Approx.11.3 x 6.3 x 1cm / 4.4 x 2.5 x 0.4in Purpose: nuclear radiation detection Battery: AA 1.5V dry battery (3pcs required) (shipped without battery) Parameters of matching Geiger tube: The pipe is a tin oxide cathode, coaxial cylindrical thin wall structure (pipe wall density 50 10cg/cm2) pulse application halogen tube, which is used to detect 20mR/h~120mR/h, gamma rays and 100?1800 off variables per points of the soft beta ray. Technical Parameter Diameter: Approx.100.5mm / 0.40.02in Total Length: Approx.902mm / 3.50.08in Starting Voltage: 350V Recommended Working Voltage: 380V Minimum Platform Length: 80V Maximum Platform Slope: 10% 80V (see M4011 below for details) Limit Operating Voltage: 550V Maximum Background Count Rate: 25 times/minute Service Life: 1x10^9 pulse 1 x Mainboard 4 x Red Gasket 4 x Small Screw 4 x Large Screw 4 x Nut 1 x Acrylic Plate 1 x USB Cable 1 x Geiger Tube 2 x Wiring 1 x Battery Box