1. Total Light Output: The total luminous flux emitted by a flashlight, measured in lumens (Lm).

2. Initial value of total light output: The maximum value of the total light output emitted by the flashlight within 30 seconds to 2 minutes of power on, measured in lumens (Lm).

3. Peak intensity: The maximum intensity of light emitted by a flashlight along the central optical axis within the solid angle, measured in candela (Cd).

4. Range: When the illumination generated on the vertical plane of the flashlight's exit axis after stable power on is 0.25Lx, the distance between the vertical plane and the flashlight's exit surface is measured in meters (m)

5. Battery life: The duration, in hours (h), during which the light output value of a flashlight drops to 10% of its initial output value when a new or fully charged battery is installed.

6. Beam angle: The angle between two given lines on a plane passing through the beam axis, which respectively pass through the center of the light source and the emitting point with an intensity of 50% of the center light intensity, in degrees (°).

7. Color temperature: The color of the light emitted by a flashlight. Unit: Kelvin (K)