Bakuda heat signature/target goggles and toe rings

Tattletale continued dishing the info on Bakuda, "Lie number two? She's fibbing about how she's detonating those bombs she has in her people's heads. She said she blows things up with a thought, but she's not wearing any external hardware on her head, and she's wouldn't have someone else do surgery on her. Too much of a control freak, too proud of her brain."

"But you don't know how she's blowing the bombs up?" I guessed.

"I know exactly how she's setting them off. Toe rings."

"Toe rings," Grue said, disbelief clear in his tone, even with his warped voice.

"She's got a ring around her big toe and the toe next to it. When she crosses one toe over the other, contacts on the outside of the rings meet and it sends the signal. She chooses the target with a system built into her goggles. It doesn't look like she's doing anything, which is probably the effect she's going for. Appearances."

[...]

"The goggles. She's seeing heat signatures. It's how she kept finding us. That ice is a blessing in disguise, since it's probably hiding us some. She must have a reason for using it. Um. Her guns are keyed to her fingerprints, so you couldn't pick up her grenade launcher and use it against her."

- Shell 4.9