I stopped buying the pett brand bags and started making my own for 1/4 the cost of their brand...... here is what you need and I have found this to work great... 1 qt size freezer bag ziploc, 1 gal size freezer bag ziploc, 3' of toilet paper, 1 cup of cat litter, 1 tall kitchen trash bag.... basically I just mimicked what they did. Everything stores in the 1qt ziploc, the cat litter goes in the kitchen trash bag, fold up the t/p, fold up the kitchen bag, fold up the 1 gal ziploc......The "used" kitchen bag goes in the 1 gal ziploc and then tossed into my trasharoo the 1 qt ziploc gets reused for the next kit made..... like I mentioned these can be made for a 1/4 of the cost of the name brand. I buy everything in bulk at costco, including the kitty litter.