This is an simply assembled DIY geiger counter. If you are interested in this product, come and have a try, it will not let you down. Two Alarm Ways: This nuclear radiation detector has sound and light indication function, the results will alert you in time. Multifunction Tool: It has the functions of real-time dose rate, average dose rate, cumulative dose rate, trend chart, etc. OLED Display Screen: A small OLED screen is adopted to clearly display the measurement results, you can see the data more clearly. ARM processor is adopted, which has quick operation speed and powerful processing function. Wide Applications: This nuclear radiation detector can detect X-rays, Rays, X-ray can detect the radioactive dose of marble, jade, sea Amoy products, iodine 131, various unknown minerals for decoration. Specifications: Material: printed circuit board Geiger tube: j321 (compatible with M4011) Screen resolution: 128 * 64 MCU: ARM Display accuracy: 0.001usv/h Detection display ranges: 0-9999usv / h Power supplys: USB, 5V, 500mA Item weight: 91g / 3.2ounce Package size: 120 * 90 * 20mm / 4.7 * 3.5 * 0.8in Package weight: 148g / 5.2ounce J321 Pipes Specification: Diameter: 100.5mm Total length: 90 2mm Starting voltage: lt; 350V Recommended working voltage: 380V Minimum Pings length: 80V Maximum Pings slope: 10% / 80V Extreme working voltage: 550V Maximum background count rate: 25 times / minute Service time: gt; 1 109 pulse Test: X radial Note: Test the cover tube close to the radiation target. Do not touching the component area during power on to avert electric shock. Please put your hand in the handheld area. Packing list: 1 * Nuclear Radiation Tester 1 * USB Cable