OTIS STAR CHAMBER CLEANING TOOL 5.56MM AR-15 PLATFORM The Star Chamber Cleaning Tool effectively cleans the star chamber of MSR/AR-style firearms in just a few twists. It features a parkerized steel scraper to remove fouling build0up and felt cleaning pads to pick up the fouling loosened by the scraper. The coated brass noise piece centers the tool in the chamber, while ensuring protection from scratches or damages to your firearm. The 8-32 threads allow attachment of a chamber brush or other scraper components for added cleaning.