I have a 10 wk old puppy and I use the plastic Super X play yard...it can be set up in 4 sections for a square..or 6 for an octagon.....We love it....
So great to place Sophie in when I can't watch her-
They have these at Walmart's , Toys R Us, and I was lazy and ordered mine off Amazon.com...it was on sale...$58....
I don't know what I'd do without it!