I have a crate purchased from PetSmart and a foldable metal exercise pen with a door, perfect for a medium-sized dog.The pen can be assembled separately or attached directly to the crate to create a little exercise area for your dog.

$20 for crate + pen together. Both the crate and pen are available for pickup immediately!

See attached images, or check out MidWest Foldable Metal Exercise Pen / Pet Playpen. Black w/ door, 24"W x 30"H and Grreat Choice® Wire Dog Crate 30"L x 19"W x 21"H.