22 Cal (5.56mm), 6.40" L Black Stainless Steel, Includes 1/2"-28 M2 QD Brake Rugged Suppressors Razor556 is a belt-fed, full-auto-rated silencer. What's the best suppressor for an AR15? Consider the Rugged suppressor: Razor556. Born from legendary performance and proven accuracy, this 5.56 suppressor was designed for the AR-15/M-16 platform.