➀ A compact GSM-based spy device is introduced that can monitor conversations over long distances, even internationally.
➁ The device is designed to be easily concealed due to its small size and can transmit audio when a specific phone number is dialed.
➂ The project requires components such as an IndusBoard Coin, SIM800L GSM module, Li-Po battery, and microphone module, along with specific code to manage the device's functionality.