Since the advent of e-mail, the internet, and text messaging, the need for amateur radio communication has definitely diminished. But there’s still a small but dedicated group of enthusiasts out there who enjoy communicating via amateur radio, also known as “Ham radio.” Most ham radio transmitters are at least the size of a lunch box, and in some cases the size of a desktop computer. But this ham radio transmitter is small enough to carry in your pocket.

Measuring just 1″ x 1″ x 0.75″, the KeychainQRP won’t transmit your voice or music, but it can send morse code signals using low-power, high-frequency radio waves when you tap on its top-mounted button. Assuming your message recipient has access to a compatible multi-band shortwave radio, they can listen to your transmissions if they’re close enough. The tiny transmitter comes in seven different amateur radio bands, and can produce a 160 milliwatt signal on a single 9-volt battery. You’ll need to attach an external SMA antenna if you want your signal to go anywhere though, and also need a ham radio operators license if you want to use one legally.

You can find all of the different frequency models of the KeychainQRP morse code transmitter for $51.99 each over on the QuirkyQRP Ham Radio shop.