Does anyone have this tailgate lock?

I want to know how it mounts...I don't want one that depends on the tailgate bolt to hold it inside. Or does anyone have suggestions on another plate style lock that just covers the entire tailgate latch hole? I'm having much trouble finding out how this thing mounts up.

http://i189.photobucket.com/albums/z166/bonnie_gragg/123.jpg

Thanks.