XTech Tactical MTX 365 380 3 Round Magazine Extension w/Spring Black 3 XTT132-BLK P365 380. Converts factory 10-round magazines into 13-round capacity while maintaining an ergonomic grip length similar to the P365X/XL. Includes a custom-engineered spring for reliable last-round bolt hold open. made in specialized factories for seamless compatibility with factory 10-round 380 magazines. Specifications for XTech Tactical MTX 365 380 3 Round Magazine Extension w/Spring: Manufacturer: XTech Tactical Color: Black Magazine Capacity: 3 Round Gun Make: SIG Sauer Gun Model: SIG Sauer P365 Features of XTech Tactical MTX 365 380 3 Round Magazine Extension w/Spring Adds +3 Rounds to P365 10-round magazines (380) Engineered extended spring for consistent feeding Quick installation with detailed video instructions Robust performance backed by innovative patented design Patents: US 11408697 B2 and US 11168954 B1 Package Contents: XTech Tactical MTX 365 380 3 Round Magazine Extension w/Spring What firearm models does the manufacturer say XTech Tactical MTX 365 380 3 Round Magazine Extension w/Spring is compatible with? The manufacturer says that XTech Tactical MTX 365 380 3 Round Magazine Extension w/Spring is compatible with SIG Sauer P365XTech Tactical XTT132-BLK P365 380: MTX 365 380 3 Round Magazine Extension w/Spring Black