APS Unprimed Primer Strips Features RCBS Primer Strips are designed to be used with the RCBS Hand Priming Tool a time-saving device that can hold up to 100 primers in the included primer tray. Not only can this tool hold 100 primers at once but it also features a RCBS patented safety mechanism that keeps the seating mechanism separate from the primer supply to eliminate the possibility of tray detonation. APS Unprimed Primer Strips Specifications Designed to save time when priming Holds up to 100 primers in the included primer tray keeps seating mechanism separate from primer supply