The same strips as on BOLSON'S unit is on the whole bottom of my 2011 Rockwood bump out along with strips also on the edges where the wear appears on the PT units. The is no wear on my fifth wheel and the bump-out has been in and out hundreds of times.
Good luck on all the units repair.
Maybe PT could learn something from ROCKWOOD!
Sid, Lois & HRH MISSY Terrible 2s SHIH TZU
2011 ROCKWOOD 8285 WS
2014 F-250 KING RANCH PS/SD/6R140/BFT
BOLIY PRO 3600SI GEN
DAYS CAMPED 2016 57 DAYS