The Phonak Invisity holds the honor of being the first in-ear RF receiver in the world.

The Phonak Invisity is the smallest – and only – in-the-ear-receiver in the world. Discreet prompting allows the production process to run smoothly and more economically. You can choose between 2 different devices. You can now program and or reprogram your invisity receiver, set your required frequencies and adjust audio level and other features at your discretion.

Guess this is the little invisible earpiece that could, operating up to 13 hours before the batteries are exhausted. Super spies and mothers who want to know their children better can always look out for one of these.

Source: Red Ferret Journal