I bought the Nachfüllfolie for the Litter Locker I and am very satisfied. Have now after a year of the first 4 films depleted and I clean the litter box about every 3 days. With the original film did I get just under 2 weeks and for me were the 7 then too expensive. For the 4 wheels no-name film I put together only 24 paid, that I have a whole year for only 6 Nachfüllfolie for the Litter Locker. The only "disadvantage" compared to the original is the one that you have to fill the sheet each time in the cassette, which is indeed friemelig, but ultimately takes less than 5 minutes. On the other hand you already smell the cat litter bit if you emptied the Litter Locker. When the bucket is closed, but I can not smell anything of it and the bucket is in my hallway. Therefore, it is definitely a great alternative because it is considerably cheaper than the Originial, one needs only a role for just over 1 year the smell remains in the bucket and we therefore only about every 2 weeks the bucket must empty. And also to the filling of the cartridge you get used to quickly. I'm very satisfied as I said it and would buy me this film over and over again.