PROMAG AR-15/M16 MAG 42RD BLK 223REM/5.56X45MM | POLYMER Manufacturer Model Number: COL-A16B Manufacturer: ProMag Model: AR-15/M16 Rifle Magazine Caliber: 223 Rem | 5.56 NATO Type: Accessory-Magazines Item Type: Accessory Firearm / Accessory Capacity: 42 Shipping Weight: 0.4 Feature: Black Polymer Optic Adjustable Objective: false Optic Reticle Illuminated: false