The Sig Sauer P365 Fuse is a compact striker-fired pistol chambered in 9mm Luger with a 4.3-inch barrel. The slide is optics-ready and carries fiber optic sights; a flared magwell and LXG grip are factory-installed. It ships with two 21-round and one 17-round magazine, with a matte black Nitron finish throughout. 
 

Key Specifications 

• Brand: Sig Sauer 
• Model: P365 Fuse 
• Caliber: 9mm Luger 
• Action: Semi Auto 
• Capacity: 17+1 / 21+1 
• Barrel Length: 4.3 in 
• Color/Finish: Matte Black 
   

Detailed Features 

• Striker-fired action with optics-ready slide (RMSc or compatible footprint) 
• Fiber optic front sight with optics-ready cut 
• Flared magwell for faster reloads 
• LXG grip module in matte black 
• Ships with two 21-round and one 17-round magazines

Owners of the P365 Fuse appreciate the longer 4.3-inch barrel relative to the standard P365, which translates to a noticeable improvement in sight radius. The fiber optic front sight gets positive marks for quick target acquisition in good lighting, though a few owners swap it for a tritium option for low-light use.

The flared magwell and LXG grip are frequently called out as genuine upgrades over earlier P365 variants. The grip texture in particular gets high marks for purchase without being abrasive under clothing. The 17 and 21-round magazine options give it flexibility between compact carry configurations and higher-capacity range use.

The trigger on the Fuse follows the P365 family pattern: clean break with a short reset that most owners find acceptable, though not exceptional by competition standards. Reliability across a wide variety of 9mm ammunition is a consistent positive, with very few break-in issues reported.