Easy way to build a strong removable bed for your Promaster buildout .
Here is a link to the e track and accessories I used and that are available
https://m.northerntool.com/shop/tools/NTESearch?storeId=6970&ipp=48&Ntt=e+track
Here is a link to the Mattress
https://www.biglots.com/product/brown-check-plush-futon-mattress/p810467097?pos=1:2