FAB Defense FX4210B Mag Extension 380 ACP +4rd for Glock 42 Black Polymer

The FAB Defense FX4210B is a +4 magazine extension purpose-built for the Glock 42 chambered in 380 ACP. This matte-black polymer floor-plate replacement installs on the factory G42 magazine and adds 4 rounds, taking the standard 6-round capacity up to a full 10 rounds.

Beyond the added capacity, the FX4210B is shaped to enable a full grip on the pistol. Contoured finger indents along the extension body give the shooter a firm, positive hold during magazine changes and improve overall control for users with larger hands. The slim polymer profile integrates cleanly with the G42 frame.

Built from durable black polymer, this drop-in upgrade requires no permanent modification to the magazine or pistol - simply swap the factory floor plate for the FX4210B extension body. Whether you carry the G42 for personal defense or use it at the range, the FAB Defense FX4210B delivers extra rounds and a more complete grip in a single, low-profile package.