Attached is my thread about Chewy's expen. It took me forever to decide which one to get. I decided on a small one from PETCO that is really for gerbils!!! This is really only for a smaller pup, mine is 2 1/2 lbs. I have had it for a little while now and my guy does fine in it. Good Luck.
http://www.yorkietalk.com/forums/showthread.php?t=11388