This is a Bianchi Inside Waistband Holster known as the 100, model 26082.
This leather inside the waistband design features a high back that provides a shield between the body and the sharp edges of the pistol for comfort and to protect clothing. It is designed to ride at the optimum angle inside the waistband to allow for a proper firing grip. A belt clip securely anchors the holster to the belt.
Features:
#100 IWB
Fits S&W Shield
Right hand