The only way to be sure to get the correct capture plate is to measure the pin box on your trailer, or an identical trailer and call Pullrite. Measuring instructions, which are quite specific, are on the Pullrite site.
For my 2011 Jayco 28.5RLS fifth wheel, I measured the pin box (which was a Dexter pin) on a similar trailer and called Pullrite; they (at that time) did not have a capture plate made for that pin. What I ended up doing is ordering my trailer with a Mor-Ryde pin box, for which Pullrite did have a capture plate.
Keep in mind that you probably will want a capture plate that you can easily remove with hand tools on the side of the road, if your trailer ever has to be towed by someone else (like a wrecker). There are capture plate adapters that some wreckers carry, but maybe not the one that shows up.
There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.
2011 Jayco 28.5RLS; 2008 Chevy Duramax; Pullrite Superglide Hitch