Are you talking about a horse/stall divider, or a stud divider (lower portion of 1st stall divider)?

I`m buying a 2007 Jamco 3H slant and the one thing it didn`t have was the stud divider, which I wanted so that I can use that 1st stall for horse stuff if I need to.  The trailer dealer where I`m buying it is fabricating it for me.  It also will be removable so I can take it out if I want to. 

If this is what you`re looking for perhaps a local trailer dealer might be able to help you?