i use the ram prime with my lee challenger press. It is a very, very, easy to use and quite sensitive in the feel for seating. Hardly any leverage is required at all and in my opinion it is superior over the older press mounted priming systems such as on the rcbs rock chucker or the older primimg system on the older lee turret presses ("T" system) for that matter. It should come with two cups for large and smal primers. I highly recomend it.