Thank you to the judges, who chose my project for the Best Product category.

I will start implementing the list below and make 3 copies of the product to send to the judges.

- Improved circuit diagram:

   + Replace Relay 3v3a with Mosfet 4N60C.

   + Use the voltage boost module (3.7V --> 7V). Used to power the Arduino pro mini.

   + The device automatically turns off the power when the voltage on the battery is less than 3.6 volts. (The device works well when the battery has a voltage greater than 3.6 volts).

   + Add 2 buttons " + , - " Used to set, increase or decrease the volume of Buzzer or vibrating motors. (Save settings to EEPROM).

   + Charge time (Poli 3.7v 300mah): From 3.6v to 4.2v is about 40 minutes.

- Edit program.

- Led on the front to catch the attention of the opposite person.

- Improved wrist strap more flexible, more comfortable.

- Add alarm function (Acts as an alarm device in the house. If there is a moving object it will emit sound).