AVAILABILITY : 0We have heard secret agents use the same kind of stuff. Well, at least security agents do. The kit comprises a walkie talkie. The signal is sent to a receiver/transmitter that is put inside a wallet (supplied). The signal is in turn sent to the earbud. This is how you, wearing the earbud, can get instructions on distance. That can be very convenient for meeting or presentations or, as aforementioned, for security people.All signals are transmitted wirelessly. All devices are very discreet (except that walkie talkie which does not need to be). Have fun with it and do not do anything that may be unlawful.Wireless audio transmitter frequencies: Channel 5: 446. 0550 Channel 15: 446. 0550Wallet Receiver: 5 AAA batteries (not included)Earbud: sr416sw battery (included)Built-in battery in walkie talkie (included)Transmission Distance earbud to wallet: 140mmTransmission Distance walkie talkie to wallet: 150mWallet transmitter: - ON/OFF - Frequency (channel 5 or 15)Walkie talkie: - Talk button - ON/OFF/volume - Micro/Earphone jack - Monitor button - Antenna portWorking temperature: -5 to 45 degrees CelsiusDimensions: - Wallet: 120 x 95 x 19 mm - Earbud: 7.9 diameter x 12.7 mm - Walkie Talkie: 114 x 57 x 32 mm