Battery tester and tachometer features: - Displays a fully charged 9V battery and can perform more than 5000 measurements. The battery compartment is easy to recharge, and the unit includes a tachometer. Lighted display for easy readability: - LCD display with backlight for clear reading, enabling trouble-free use in dark environments. Energy-saving operation: - Auto and manual saving modes conserve power and help extend the life of the device. Digital tachometer with digital display: - Contactless digital hand tachometer with stable performance and high accuracy, minimizing the impact on the objects being tested. Use scenarios: - Automotive maintenance: quickly check and monitor the RPM of small engines, pulleys, fans, or other rotating components during diagnostics. - Electronics and appliances: measure RPM of cooling fans or small motors in devices without contact to avoid interference. - Workshop and hobby use: verify RPM of power tools, hobby motors, or mechanical assemblies for calibration or quality checks.