Magna-Matic Defense's CRT-15 has been redesigned to improve its current features, and add an important new feature. The reamer-style head has been redesigned to improve its scraper edges to maximize carbon removal from the bolt carrier of AR-15-type rifles. The new feature of the CRT-15 is "Firing Pin Cleaning" the firing pin drops into a hole, where there are two small scrapers that remove the carbon build-up from the firing pin face.