Dead Air USB-C Mic Blocker

Plug it into a USB-C port and your phone, tablet or laptop thinks a microphone has been connected. It switches over to that "mic", which hears nothing, so the built-in microphone goes quiet.

No apps, no batteries, no settings. Pull it out and everything goes back to normal. It is a tiny aluminium plug with a loop hole, so it can live on your keyring.

The specs: aluminium body, USB-C plug, 23.7 x 12.1 x 6.8 mm, 5 g. Black, silver or grey.

What it does not do: it only works on devices that switch to a USB-C audio accessory when one is plugged in. Not every phone or laptop does, so test yours with a quick voice memo before you rely on it. Some apps can still choose the built-in mic, and a Bluetooth headset can take over. While it is plugged in, calls and voice notes go silent both ways, and your speaker may go quiet too. It only affects the device it is plugged into: it is not a jammer and does nothing to anyone else's phone.