The Sig Sauer laser-engraved TXG Grip Module uses a tungsten-infused polymer that is then molded into the part. This patent-pending process results in a grip module that has the weight of steel and the flex of polymer. Sig Sauer took this a step further and laser-stippled the grip module for a more aggressive gripping surface. Install your P320 Fire Control Unit into the grip module and you'll have one of the flattest, softest shooting pistols on the range. Bote: Requires complete P320 Fire Control Unit and X5 or Full-size slide assembly.