FAB Defense FX4210B Mag Extension for Glock 42 – .380 ACP

Description

The FAB Defense FX4210B is a magazine floor-plate replacement designed specifically for the Glock 42 (.380 ACP). It increases on-board capacity by adding 4 rounds to the factory magazine and incorporates an ergonomic profile to improve handling when the magazine is inserted. Construction uses fiberglass-reinforced polymer for a durable, lightweight component that maintains the original magazine spring functionality.

Key Specifications

• Fits the Glock 42 handgun only.
• Function: floor-plate replacement that increases magazine capacity.
• Adds 4 rounds to the existing Glock 42 magazine.
• Total magazine capacity becomes 10 rounds when used as described by the manufacturer.
• Constructed from fiberglass-reinforced polymer for strength and reduced weight.
• Finish: Black.
• Contoured finger indents provide a firm, repeatable grip during magazine manipulation.
• Original magazine spring compatible thanks to an innovative spring plate design.
• Enables a full grip on the handgun when the extended magazine is installed.

Compact and purpose-built, the FX4210B offers a practical capacity increase and improved ergonomics for Glock 42 owners who prefer a fuller grip and faster magazine handling. Its polymer construction and spring-plate compatibility make it a straightforward upgrade that integrates with the factory magazine components.