The Smith & Wesson Model 340PD is a pistol ultra-light J-frame five shot snubnosed revolver chambered for .357 Magnum.
NCIS/Mossad Liaison Officer/NCIS Special Agent Ziva David is seen dual-wielding this pistol alongside her SIG-Sauer P226 during the Season 6 episode, Dead Reckoning (episode). When Ziva isn't using this weapon, she keeps this in an ankle holster.
In the Season 8 episode, Dead Air (episode), Ziva is seen holding the pistol before hiding in an ankle holster while going undercover.
Ziva is seen holding the weapon again during a stakeout in the Season 10 episode, Devil's Trifecta (episode).