The Score Hi follower is for Staggerfeed only. Does not work on Centerfeed actions. SSS is the only place I have even seen making a CF style follower, other than the home made versions posted earlier in this thread.

The Score Hi brand follower is designed to sit on top of the follower and basically block the magazine while also providing a trough for single shot loading with the wider mouthed staggerfeed magazines. The Centerfeed mag design just won't allow for that style of follower and as such SSS came up with their follower that basically replaces the mag. I find putting the follower in the empty magazine well under the SSS follower keeps it in place vey nicely.