It’s often said that money talks, but no one ever meant it literally. However, Register Hardware’s come across a wallet-shaped gadget that lets you have covert conversations with your cash. Sort of.

The Zrad covert earbud wireless receiving kit: stealth

The Zrad covert earbud wireless receiving kit consists of an earpiece and a small credit-card size receiver that slips into a wallet. The receiver has a maximum transmission power of 300mW and picks up transmissions from other undercover operatives working in the field, provided they're no further than 3km away. It then relays the conversation to your earpiece.

According to the retailer, the covert kit is perfect for “law enforcement, casino security and protection personnel”, or just a bit of pretend James Bond action. The disadvantage is that you can’t talk back to anyone, so you may have to work out a system of hand signals and blinks.

The Zrad covert earbud wireless receiving kit is available online now for $150 (£75/€100). Details of a UK release date are set to be handed over under the big clock in the park at 09.00 hours.