This is the XGRIP adapter for SIG P320 Compact / P250 Compact pistols. The XGRIP will slide on SIG P320 full-size 9mm magazine.

This XGRIP adapts the SIG P320 17-round high capacity magazine for use in the SIG P320 Compact, incorporating the larger magazine into the P320 Compact’s grip and increasing the gun’s capacity to 17 rounds.

XGRIP products allow you to incorporate larger magazines into more compact pistols, maximizing capacity and control.