F.a.b. Defense Plus 4 Magazine - Extension Black For Glock 42

The F.A.B. Defense Plus 4 Magazine Extension Black for Glock 42 is a purpose-built capacity enhancer designed for shooters who demand reliable extra rounds in a compact package. Purpose-built for concealed carry platforms, this extension addresses the primary limitation of single-stack subcompacts: magazine capacity. Law enforcement, civilian defense carriers, and competitive shooters rely on magazine extensions to close the gap between firearm design and practical engagement requirements.

Manufactured by F.A.B. Defense, a leader in tactical polymer components, the Plus 4 extension adds four rounds to standard Glock 42 magazines through engineered polymer geometry that maintains feed reliability. The design features a witness hole for round count verification and uses dual-spring compression technology to ensure consistent chambering under duty conditions. The black polymer construction resists corrosion and UV degradation while remaining lightweight at 0.15 pounds, preserving the carry characteristics that make the Glock 42 popular for off-duty and backup roles.

Glock 42 owners in both law enforcement and civilian markets benefit most from this extension when prioritizing balanced capacity without sacrificing concealability. Installation is tool-free and takes seconds—simply remove the magazine baseplate, stack the extension sleeve, and reinstall. The Plus 4 remains fully compatible with standard Glock 42 magazines and does not interfere with holster indexing for most inside-waistband and appendix carry platforms, making it an immediate upgrade for shooters seeking additional tactical options.