Amend2 S300 Hybrid Grip Module. MSRP $59.99

This from the Amend2 WEBSITE:

The Amend2 S300 Hybrid Grip Module is a grip module designed to function with Sig Sauer P320 Style Fire Control Units and Complete Slides, while allowing use of Sig Sauer P365 Style Magazines. the result is an easily convertible concealed carry firearm, that can transition back to a full size duty gun in seconds. 

-Compatible with Sig Sauer P320 Style compact and full size slides (Sub compact compatible with use of compensator)
-Compatible with Sig Sauer P365 Style 10, 12, and 15 round mags
-Compatible with all Sig Sauer P320 Style holsters
-Full size accesory rail allows attachment of full size lights and lasers

-Utilizing P320 style slides allows for use of full size optics. 

-Covered by the Amend2 Lifetime Warranty
DISCLAIMER: This product is not manufactured, authorized, endorsed,
or warranted by Sig Sauer. Sig Sauer does not warrant or represent that
this product is compatible with Sig Sauer pistols. 
Sig Sauer, P320 and P365 are trademarks owned by Sig Sauer, Inc.