This is one of my favourite pieces of the show: Nick's stunt jacket that was worn by David Giuntoli in the Season 5 episodes "The Taming of the Wu" (5.19) and "Bad Night" (5.19). Since it is only written "stunt" inside and no mention of "double", I think it may have been used by David himself when doing his own small stunts. But it's just a hope/guess. I wonder what the word "stringer" means... I added a picture of each episode (thanks to screencapped.net) as well as a promo photo where we can also see the jacket.