This is a X-GRIP known as the Mag Spacer, model GL19-23.
This XGRIP adapts the GLOCK G17" G22 or G31 full size high capacity magazines for use in the GLOCK G19" G23 or G32 compact pistols" incorporating the larger magazine into the grip and increasing the pistol's capacity.
Features:
Improved Comfort, Control, and Accuracy
Increased Capacity
Secure Fit
