Features: The utility model has the advantages of large effective sensing area, convenient use, high sensitivity and the like. It is highly adaptable to ambient light and can be used indoors and outdoors at day and night. You can save 80 sets of data, and you can see the average value. Specifications: Voltage: DC 6V Battery (not included): 4*AA battery Working temperature: -30℃-60℃ Accuracy: test error ≤0.5% Measuring range: 0-3000M/S (FPS range 30-9999) Standard tripod can be installed Item size: 330 * 80 * 44mm / 12.99 * 3.15 * 1.73in Item weight: 436 grams / 0.96 pounds notes: This product is infrared radiation type, the light source has been integrated in the machine, no external light source is needed. Recommended for low-light environments. The darker the ambient light, the better the machine performance. Under outdoor use and strong light conditions, a hood must be added. When measuring the velocity of the projectile at a higher speed. Please take appropriate protective measures. In order to prevent the projectile from rebounding after hitting the machine and causing damage. When installing, pay attention to the marks on the left and right sides of the light bar, and the light bar with lights faces down. Package includes: 1*Speedometer 3*Heat shrink tube light bar 4*Pure copper rod 1*Screwdriver