Joey Bed....Is the name of one Brand,
You get everything except the plywood floor
You assemble it to the width you need for your compartment
I built my own for my champion 3200 inverter generator, using heavy duty slides I purchased from Amazon
In the past 12 years, I've done this for 3 Class A we owned
The first time I bought the slides from a wood working supplier,, after that from Amazon , but same brand heavy duty pantry slides, over $100 for the slides 3 section full extension 26 inches IIRC , the longer slides the higher the price, 8ft slides that go 4ft either way for pass thru compartment install, are going to be big bucks