(1) Switch to the ON, the flash will start charging (the charging indicator is dim). After several seconds, the charging indicator turns red and TT520 is ready to shoot.

(2) For a test flash, press the test button. After use, press the ON/OFF to OFF to power off.

(3) If the red charging indicator lamp flickers in every 1s, it indicates low battery. In such case, the power will turn off automatically and you need to replace the batteries.

(1) The flash unit has 8 steps of power output control which indicated by 8 pieces of LED lamp for different level.

(2) Press "+" to make power higher and they are 1/128,1/64,1/32,1/16,1/8,1/4,1/2,1/1.Otherwise, press "-" to make power lower.

Press the MODE key to M Mode. In this mode, you can set TT520 on to your camera hot shoe or speedlite trigger hot shoe to trigger the flash unit. When shooting, adjust the flash power and press the camera shutter, the flash light will flash under the camera synchronous signal.

(1) Press the MODE key to S1 Mode. The Mode is applicable for slave flash in order to create many lighting effects. It is respectively applicable for manual flash environment.

(2) When the flash is S1 mode, it will fire synchronously when the master flash fires, comparable with the effect by the use of radio trigger.

Press the MODE key to S2 Mode. The mode is applicable for slave flash in order to create many lighting effects. It is respectively applicable for TTL flash environment. The flash unit won't flash synchronously with the first flash but the second flash from the master flash.

(1) To save battery power, the flash will enter stand-by state in about 30 minutes of idle use. Press any button to wake it up.

(2) In S1/S2 mode, the flash will enter stand-by state in about 60 minutes of idle use. Press any button to wake it up. (3) In Power-saving mode, the charging indicator flickers in every 3 seconds. Other indicators are turned off.

(1) Protection in continuous flashes

To prevent the flash head from getting too hot and damage, please do not flash over 20 times when in power lever 1/2, 1/1. Please cool down the flash unit for at least 10 minutes. The over-temperature protection function will be activated if you continue to flash after 20 times. In this state the charging time will turn to 10-25s. Please cool down the flash unit around 10 minutes and it will turn to normal state.

(2) Systematic over-temperature protection

When the inner circuit is over-heating, which indicates over use of the flash unit, the inner circuit will shut down power automatically. The flash unit will turn to normal state after the inner circuit is cooled down.