Global Sportsman AR15 AR-15 M16 .223 Rifle Steel Bolt Carrier Carbon Scraper Gun Cleaning Tool Breaks Loose And Removes All Excess Carbon Buildup Which Can Prevent Proper Cycling Doesn't Damage The Metal Bolt Carrier When Used Properly Made Of High Quality Steel And A Sturdy Plastic Handle : 6.5" Length Provides The Proper Alignment In That Hard To Reach Area - Simple And Quick To Use Better Than Brushes, Tools, Or Solvents That Have Been Known To Cause Damage