XTech Tactical MTX 365 Magazine Extension for Sig P365, +3, 9mm

The XTech Tactical MTX 365 magazine extension is a capacity and grip upgrade designed for the Sig Sauer P365 platform. It increases compatible 10-round magazines by three rounds while extending the grip profile to match P365X/XL ergonomics. Supplied with a custom spring and engineered for reliable feeding and last-round bolt hold open, the extension is manufactured in the United States.

Key Specifications

• Capacity increases from 10 to 13 rounds.
• Designed for Sig Sauer P365 compatibility, including Wilson Combat grip modules.
• Constructed from injection-molded polymer.
• Includes a custom-engineered spring to support reliable feeding and last-round bolt hold open.
• Color/finish is black polymer.
• Fits factory 10‑round P365 magazines and many aftermarket grip modules.
• Listed dimensions are 1.20 x 3.80 x 6.30.
• Listed height/width/length values are 1.2000, 3.8000, and 6.3000 respectively.
• Listed weight is 0.07.
• Made in the USA: Made in the USA by XTech Tactical.

The MTX 365 extension provides a straightforward, practical upgrade for users seeking added capacity and improved grip ergonomics without changing magazine baseplates. Its compatibility with factory magazines and common aftermarket modules, paired with U.S. manufacture and a custom spring, makes it a reliable option for everyday carry and range use. Note: the product listing indicates no direct ship to California.