Features: High measurement accuracy and display resolution; Quick response and measurement:It can display fast-tracking abd real-time measurement of optical power when output power changes; Wide measurement range:it can provide 80Db of optical power measurement range; Six Calibrated wavelength; Provide absolute optical power measurement and relative power measurement; Real-time monitoring and displaying the battery level.Warning notice is available when the battery is low; Auto-off function; Backlight LCD display; AAA batteries which is more convenient to carry;