My Monaco La Palma came with that from the factory.
A rubber strip on each side of the bedroom slide mounted diagonally.
Put it on and try it out. Worst case situation you can remove it.
Mine have been on for 7 years with no problems.
2004 Monaco La Palma 36DBD
Workhorse W22 8.1 Gas Allison 1000, 7.1 mpg
2000 LEXUS RX300 FWD 22MPG 4020 LBS
US Gear Brakes