All-In-Two (AI2)

AI2s are either covers with a way to attach the insert to the inside (snaps or velcro, usually), or AIOs with a way to detach the insert from the side. The difference is whether the inside of the shell is waterproof (meaning you can wipe any pee off and it’s dry and ready to reuse with new inserts), or not (you have to change the shell each time you change the diaper)