RCBS Primer Strips are designed to be used with the RCBS Hand Priming Tool. This tool is a time-saver that can hold as many as 100 primers in the included primer tray. In addition to holding up to 100 primers at once, the RCBS Hand Priming Tool features a RCBS patented safety mechanism that keeps the seating mechanism separate from the primer supply, eliminating the possibility of tray detonation.