I got my dog pack from REI. The model I have holds about 6-8 discs, but there are several brands you and your dog can choose from. I'd suggest visiting one of the REI stores around Atlanta. There's one on Barrett Parkway near Town Center Mall in Kennesaw, one behind Perimeter Mall on the North side of Atlanta, one on the Southbound I-85 feeder road just South of Clairmont Road a few miles North of the downtown connector, and one in Buford near the Mall of Georgia. If you visit the store at I-85 and Clairmont, tell them Lewis sent you, 'cause I worked there a couple of years ago.