Aero Precision APRA500104A: The Atlas S-One is machined from 6061-T6 aluminum, and designed with size and weight in mind, which provides the perfect handguard for your lightweight build. Aero\'s proprietary Atlas attachment system is a durable and dependable mounting platform, maintaining a slim profile while still providing the strength and stability. This 12.6\" model has a black hardcoat anodized finish and M-Lok.