Linda Hunt stars as Hetty Lange on NCIS: Los Angeles.

She's in charge of the technology that Henna and Callen use on the show. She's pretty much like the Q to their James Bond.

Hetty Lange Quotes

(To Nate as he leaves) Keep you wits sharp, your heart open and your gun loaded.

Hetty

Callen: Is there a military angle to any of this?
Hetty: No, but Detective Deeks is still the Liaison Officer with the LAPD, which makes him about as close to one of us as it gets.