Luminox 8251 EVO Ultimate SEAL - Daniela Ruah - NCIS: Los Angeles
The model Daniela Ruah wears the model with black dial, black case with metal bezel and black rubber strap.
Luminox watches are famous for the use of tritium to illuminate the hands and numerals of its products, which gives a bright glow in dark circumstances, even when the watch hasn't been in the sunlight for a while. Luminox was originally designed for United States Navy SEALs, so is an appropraite choice for Daniala Ruah's character in NCIS (Naval Criminal Investigative Service).
According to CBS, the characters Callen and Sam also wear Luminox watches most of the time, series 8800. Sam wears a Blackout model. When they go undercover, they wear a different watch. We have spotted Sam (played by LL Cool J) with a Suunto X-Lander as well.