All In Two Nappies
An all in two reusable nappy come in a couple of forms - some have a stay dry lining on top of the PUL, other don't. Some have pockets, and other's don't. They are kind of a hybrid between an all in one and a pocket nappy.
If the all in two has a stay dry lining sewn onto the outer wrap, the whole nappy needs to be changed, however ones that don't have this (like the Pop-in), you can simply pop out the insert and replace, continuing to use the same outer wrap 3-4 times unless soiled.
Brands include Mother-ease and Bells Bumz.