All in 2/Snap In Cloth Nappy:

All in 2 nappies come with two parts, the outer waterproof shell and the snap in inserts. The idea with the snap in inserts is that you can just change the snap in insert if the whole nappy is not soiled. This means less washing as you are re-using the outer shell again, and just replacing the inserts until a full change of shell and inserts are required (when soiled). This system saves on washing machine space and is cost effective as you don’t need to purchase as many shells as you would inserts.

Examples : Weebots Double Gusset/Snap in Nappy

Click here for washing instructions