This is a Raven Concealment Systems Inside Waistband Holster known as the Vanguard, model VG2MPSHBKOH.
The VanGuard 2 is a minimalist IWB holster. Unlike traditional IWB holsters" the VG2 covers only the trigger guard of your weapon. This unique design eliminates the bulk of a traditional holster" while providing a level of safety and security not attainable by simply sticking a pistol in the waistband of your pants.
Features:
Fits M&P Shield 9/40
Inside the waistband holster