Features: This counter set features a tube to detect rays and radiation, with detecting ranges of 20mR/h–120mR/h for and 100–1800CPM. Double Power Supply Option:Supports both battery (3x1.5V or 4x1.2V) and USB 5V power input, ensuring flexible operating in outdoor or desktop setting. Open Source Design for Customization: Features a clearly labeled PCB (RadiationD v1.1) with accessible components, enabling circuit modifications and integration with microcontrollers. Real Time Alert :Equipped with a buzzer and LED indicators that triggering upon radiation detecting. Includes an auditory output port for connecting external speakers, enhancing operational awareness. Durability Construction: Includes mounting hardware for easy assembly, perfect for electronics enthusiasts and STEM applications. Specifications: Component: ABS. Dimensions: 118x63mm/4.64x2.48in 5V power supply, or 3x 1.5V batteries; 4x 1.2V batteries, current: 12mA - 30mA. Supporting tube parameters: Technical parameters Diameter: Φ10±0.5mm. Total length: 90±2mm. Starting voltages: <350V. Recommended working voltages: 380V. Minimumed floor length: 80V. Ultimatedly working voltages: 550V. Background count: 25 times/min Life: >1×10^9 pulses. Package Includes: 1PC Welded Counter 1PC tube (J305 or M4011 type) 1PC power cord note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.