In the video game series Metal Gear Solid, the protagonist Snake uses a wireless communication device called a codec that resonates with the bones in his ear and skull to communicate, as if by telepathy. Now, the US military is making that technology a reality.

The Pentagon just cut a $10 million dollar deal with Sonitus Technologies, to develop a wireless, tooth-based, communication device that the company calls the Molar Mic. This injection of cash is just the latest round of military funding for Sonitus, which received early funding from In-Q-Tel, a CIA investment company in 2016.

The Molar Mic slides over a back molar in the user’s mouth—each piece is custom fitted—and uses near-field magnetic induction (think of it as short-range Bluetooth that’s not impeded by the human body) to make a connection to the rest of the kit. Users push a button to activate the mic.

The mic is waterproof and its speaker works using bone conduction, meaning it uses vibrations to transmit sounds to the cochlea through the bones in the user’s skull. “Sound will appear to come from ‘inside the head’ instead of from the outer-ear as one would be used to,” Sonitus explained on its website. “Bone conduction hearing enables the operator to simultaneously hear through the outer-ear as they normally would.”

According to Sonitus, the molar mic can pick up a whisper with no problems and loud environments like, say, helicoptering over the ocean, won’t hinder communication because the user’s mouth provides a natural shield against ambient noise.

The technology has already been tested in Afghanistan and during relief efforts during Hurricane Harvey. According to a press release from Sonitus, a pararescueman deployed to help flood victims near Houston used the Molar Mic to communicate with a helicopter crew while airlifting an injured civilian out of the water. “The crew was amazed that they could clearly hear the PJ in these conditions,” Sonitus said.