Compact Spy Ear-- Perfect for Listening in on Parents! For junior agents, the Spy Ear is A First Class Product. Says so right on the package. It's a small, belt-clipped amp with a microphone plus earbuds on a 2-foot cord. Includes on/off/volume switch and runs on an AG13 or L154 button cell battery, included along with a spare, but they could be running low. (Surplus!) Good for listening in on parents.