Every baby is different and even one baby's overnight absorbency needs will fluctuate as they grow - this system provides all you'll need to keep your little one in cloth overnight from around 10 lbs to 30/35 lbs.
Snappiable Cotton French Terry Outer
With the Regular Snap In (9) layers and the NB Snap In/Booster (3) layers, the fitted itself provides 17 layers of absorbency.
For older infants use the regular snap in without the booster for a total of 14 layers.
For younger infants use the NB insert/Booster snapped in and the lay in booster if needed for a total of either 8 layers or 11 layers.
This is a fitted and is not waterproof. For the ultimate in night time diapering pair this fitted with a good set of wool shorties or longies. My favorite pair is from RCarver on www.diaperswappers.com.