Well, when I snapped these things in place my wife says, "reminds me of when we wore garter belts".
I've converted a liberty to twin beds. The mattress is much narrower than the standard 'twin' sheet sets. These things allowed me to use twin size fitted sheets on the narrower mattress and keep everything tight. Thought perhaps folks with Freedom and Spirits might be able to use em around the back corner of the mattress?! From Wal-mart. :)
<img src=http://www.fiberglassrv.com/board/uploads/3ef0e575ed78aCasita twin bedding straps.jpg/>
<img src=http://www.fiberglassrv.com/board/uploads/3ef0e5acc11fcCasita twin bedding.jpg/>