Product Overview The SIGM400 5.56 NATO rifle with a 16 in barrel delivers a semi-automatic platform built around a Romeo-MSR Gen II optic, a telescoping stock, and an aluminum M-LOK handguard in a black finish. The package includes a 10-round magazine. Key Features Caliber: 5.56 NATO Action: Semi-automatic Barrel length: 16 in Optic: Romeo-MSR Gen II Stock: Telescoping stock (Tele Stock) Handguard: Aluminum M-LOK HG Finish: Black Magazine included: (1) 10RD MAG Specifications Product name: SIGM400 Cartridge: 5.56 NATO Fire control: Semi Barrel length: 16 in Optics model: Romeo-MSR Gen II Handguard system: M-LOK (aluminum) Magazine capacity: 10 rounds Color/finish: Black Benefits and Performance Notes With a 16 in barrel and integrated Romeo-MSR Gen II optic, the SIGM400 is configured for quick target acquisition and consistent sighting alignment. The telescoping stock supports adjustment for different shooting positions, while the aluminum M-LOK handguard provides a modular mounting interface for accessories. Use Cases Range sessions with 5.56 NATO ammunition Training activities requiring a semi-automatic 16 in configuration Target-focused setups benefiting from an included red-dot optic Accessory-equipped builds using an M-LOK handguard