C.M.
We used the white mesh type rail that I think my husband purchased from either BRUs or Wal-Mart. The guard rail has a portion of it that is meant to go under the crib mattress so it stays in place. My husband had to kind of rig it to stay in place, but it worked great and there was just enough room for my daughter to get in and out of the converted crib all by herself. Hope this helps, good luck.