I got the fuzion 310 with the monster pk.
It had the D rings welded to the frame.
When we where looking at other toy hauler's some of the D rings was a joke
look like they would not hold down a kids bike
We have a 16' cargo trailer we pull and haul our bikes in I installed these with the back plate and after like 7 years still holding strong.
If the next toy hauler I get dose not have the D rings welded to the frame
Ill just spend the day and install them good peace of mind for the money.
Here's what I have in my cargo trailer.
http://www.etrailer.com/Trailer-Carg...ophy/RR5K.html