Super convenient to spin clean entire exterior of your .30 cases including the base. Works with cases from 2.008″ to 2.630″ long. Most use 0000 steel wool (not included). While a case is spinning its easy to clean the primer pocket with an appropriate tool made for this purpose. Chucked the spinner in an electric hand drill, or drill press, turn at 400 to 500 rpm. DO NOT WRAP POLISHING MEDIA AROUND YOUR HAND, DO NOT USE GLOVES, GRIP CASES WITH THE POLISHING MEDIA NOT THE BARE HAND. POSTPAID!