Installation and mounting - Install into a mounting hole with 85 mm diameter and 70 mm depth. Insert the gauge and fasten securely. Adjustable speed ratio and idle - Speed ratio adjustable from 1 to 300. Use the back button to adjust. - Idle speed is typically 600 to 800 rpm. - Refer to the owner manual for detailed setup and usage instructions. Engine compatibility and signal sources - Suitable for both diesel and gasoline engines. - Tachometer can receive signals from engine, ignition coil, crankshaft sensor, or tacho sensor. Display and maintenance data - Displays both rpm and running hours. - The hourmeter cannot be reset. Use scenarios - On-site engine diagnostics and tuning: compatible with diesel or gasoline engines, adjust speed ratio for precise testing and monitor RPM in real time. - Fleet maintenance scheduling: track engine running hours to plan maintenance and service intervals. - Test bench or training setup: connect to common sensors (engine, ignition coil, crankshaft, or tacho sensor) to simulate and measure performance during development or education.