I purchased and then returned 4 different
exercise pens from pet stores.  This is the 
absolute best pen.  Since I bought 2 pens I
can configure all sorts of sizes depending on
my needs.  When I take my little Papillon, Minnie,
on a trip I take 4 panels with me for a little pen
and leave 4 panels at home all set up for our 
return.  You cannot go wrong purchasing this
pen.  I highly recommend it!!!!