ABUniverse's first big hit product was their Space diaper. Since then they have introduced three other products that were just different "shell art" for the same physical model of diaper as the Space. Those were the Little Paws (with a babyfur theme, those are still a big hit), Sissy (which of course had a pink / sissy theme, didn't sell well, not currently offered) and the most recent addition is the Simple. (all white except for a small lightweight black-and-white ABUniverse logo) The Simples were introduced about the same time as they opened their "Sticker Store", selling a mix of littlefur / babyfur by two different contracted artists. You could buy the Simples and then apply any sticker you wanted to the tape panel, they're wide and colorful. It's a lot cheaper for everyone involved for them to stock one model of diaper and 20 different kinds of stickers than 20 different models of diaper.
I personally prefer just straight up all-white diapers myself.