Hi Laura,
 
I haven't seen the plexi-barriers you are talking about, but I have "made"
my own.  I go to Lowes and have a piece of plexi cut 24" high, and then
40-60" wide (depending on the doorway) and then just bend them into shape
at the doorway.  Usually costs me about $12-15 each.  It is a good idea
however to put some colored tape, etc on them as they are nearly invisible
unless you are paying attention and we have walked into and broken a
couple.  Doesn't hurt us any - but it is money down the drain.  They are
very effective for the ferrets and portable so we can change from one
doorway to another with no problem.  My male "climber" can get over the
ones that I had cut to 20", so now we stay at 24" high.
 
Karla
Meep and Daisy
[Posted in FML issue 2868]