Happy Heinys One Size Diaper cover w/gussets: This is an absolutely wonderful one size diaper cover that will fit most babies from 8-35 lbs. We have used the softest fold over elastic we could find for the entire edge of the cover and gussets. These gussets are wonderful for holding in the typical runny breastfed poo as well as most "illness poo". With a stuffed Happy Hempy this combination is a bullet-proof combination for over-night.