WHISPER TI 5.56MM SILENCER BLK SP-WHISPER556BLK28 Manufacturer Model Number: SP-WHISPER556BLK28 Manufacturer: Wilson Combat Model: Whisper Caliber: 5.56 x 45mm Type: NFA - Silencer Item Type: NFA Finish: Black Armor-Tuff Overall Length: 6.3" Weight: 17.8 oz. Shipping Weight: 1.0 Feature: Multi-Caliber Rated Feature: Rapid Thread Muzzle Brake Optic Adjustable Objective: false Optic Reticle Illuminated: false