G&D Smart Electrical Control Unit (ECU) for M4 DTW Series

Option ECU set for G&D M4 DTW Series.
Custom setting for switch between full-auto or adjustable burst mode after install this ECU Set.
Can change setting during survival game / wargame.

Adjustable Burst Mode:
1. Connect the battery and switch to Auto mode.
2. Press and hold the lower part of the bolt catch button for cutting off the power supply before all setting completed.
3. You will hear a "beep" sound (Red night also on) after hold the trigger not more than 5 seconds.
4. Then push the trigger for few times which same as the burst round you want (press 3 times for 3 round burst), than hold the trigger at your last round until hear the beep sound (red light goes off as well) for completing the setting.

Switch between full-auto mode and burst mode:
1. Connect the battery and switch to semi mode.
2. Press and hold the lower part of the bolt catch button for cutting off the power supply before all setting completed.
3. You will hear a "beep" sound (Red light also on) after hold the trigger not more than 5 seconds, then hear another beep sound after 3 seconds (red light goes off as well) to show setting is completed.