This is a X-GRIP known as the Mag Spacer, model 1911C2.
The patented XGRIP 1911c2 adapts the full size ACT-MAG (1911 45acp) 8 round magazine with plastic floorplate to function and blend into the frame of the compact 1911 Officers pistol. Compatible only with the Act-Mag / NOVAK and Mec-Gar (model 17-7PH) 1911 magazines.
Features:
Improved Comfort, Control, and Accuracy
Full Size Magazine Capacity
Protects Extended Magazine
