Animals-Dog: Pet Park Indoor Potty Dog Grass Mat Pad Training Petzoom Puppy Patch Patio 2015 - BUY IT NOW ONLY $30.38
DIY dog grass box! Easy to make and less than $40 at Home Depot!
How to make a doggie potty on an apartment balcony. http://superdogcharliepants.blogspot.jp/2011/06/dog-potty-for-patio-build-your-own.html
I made this doggy potty island out of kiddie swimming pool, palm & 3 pallets of sod for doggys with limited yard opportunities!!!