Compatible with all APX Full Size standard magazines and designed to increase the magazine capacity by 2 rounds (if 9mm caliber, if .40 caliber the capacity is increases by 1 round) and to improve the grip during magazine extraction due to aggressive milling. Will fit all APX series double stack magazines, all calibers. Details: Made in ItalyEasily attaches and detaches from the magazineStandard 2mm allen key wrench is needed for assembly the devices and disassembleTwo piece design (pad and retention screw)Designed specifically for the Beretta APX seriesCNC machined from billet aluminumHard Anodized Beretta APX +2rd Magazine Extension E02935