This is a X-GRIP known as the Mag Spacer, model 1911C1.
The patented XGRIP XG1911c1 adapts the full size 1911 45acp 7 or 8 round metal floorplate magazines to function and blend into the frame of the compact 1911 Officers pistol.
Features:
Improved Comfort, Control, and Accuracy
Full Size Magazine Capacity
Protects Extended Magazine
