Features: 100% brand new, high quality. This product can be used in all gasoline engines with spark plugs. This tachometer is easy to use and is suitable for two-stroke single-cylinder, four-stroke two-cylinder, and gasoline engines that are fired once a week; more suitable for: testing the speed of chain saws and lawnmower gasoline engines, measuring speed range: 100RPM to 30,000RPM. Due to the inductive design, place the meter near the spark plug cable and it will test the data,Method 1: Keep the meter 3-5CM between the spark plugs and then test. Method 2: Insert the pickup wire into the hole of the meter and keep the metal clip clamped on the spark plug cable. LCD display/low voltage/built-in battery power supply/inductive design/safe and reliable. Press and hold the MODE button to view historical high-speed data regularly. Timing range: 1 minute ~ 99999 minutes (MIN). Speed mode setting: long press the (SET) key, the screen will play 01, 02, 03, 04 in sequence: (Screens 01, 02, 03 respectively display the speed modes corresponding to various engine strokes) Factory default values It is 02 speed mode. When you release the button with your finger, the displayed data will flash for 3 to 5 seconds. After stopping, confirm that the speed mode is activated and you can measure. System data reset function: long press (SET), the screen will display 01, 02, 03, 04 in sequence; when the screen displays 04, it will flash for 3 to 5 seconds. When your finger releases the button, the display data flashes for 3 to 5 seconds and stops, then enters the system reset mode, press and hold the MODE key and SET key at the same time until full screen display (reset to zero). Specified working time and speed data resetThe product will enter power saving mode when not in use and will enter working mode once tested. Specifications: Type: Digital Tachometer Color: Black Measuring Range: 100-30000 RPM Timing Range: 1-99999 Minutes Measuring Accuracy: 1% Resolution: 100% Power Supply: 1x CR2450 Coin Battery Retail Packaging: Yes Package includes: 1 set x tachometerDo you do direct shipping? Yes, we do. If you have any questions, please contact us. Is the production material safe? All products are 100% brand new, operational and carefully inspected before shipment. When will the package be sent out? We will ship your order within 5 working days. Delivery times vary from country to country and are affected by weather, public holidays, etc. If the order is not received within the stated time, please contact us. How to get a refund? If the item is not as described or defective, a full refund is available. If you have any further questions, please click Help