To determine which surveillance transmitter or listening device fits your need, use the following guide:

• Lithium Transmitters tend to have special features such as remote activation, long term operation, voice activation.
• Digital Surveillance Transmitters tend to be able to send data bursts, be it encryption, voice, or computer.
• Concealable Transmitters offer body wire audio surveillance and tracking capabilities, favored for undercover surveillance.
• Mains Transmitters are battery-free and use power lines to operate.
• Phone Transmitters can help monitor telephone and room conversations, some models battery-free.