Boo Bear Buns hemp contoured diapers are one size fits all hybrid diapers. It's a hybrid because most contoured diapers do not have elastic, and some do not have wings. Fold down the front to fit a newborn and leave up to fit a toddler up to 35 lbs! Buying a one-size diaper is more cost effective (24 diapers vs. 24 diapers in 3 sizes=72!). They can be used with pins or a Snappi. (Snappi does not work as well as it does with cotton, but if you push the teeth in the fabric, it will hold.) You may also set inside a good fitting cover. Since hemp is more absorbent than cotton, the 3 layers are significantly less bulky than a cotton diaper of similar absorbency. Every baby will appreciate that! Handmade in Maine, USA. Why Hemp? Our 55% hemp/45% organic cotton fleece diapers are very soft. Hemp is 4-8 times more absorbent than cotton and has natural anti-bacterial properties! It is wonderful for babies with sensitive skin. Absorbency refers to the soaker layers 1 is 1 layer, 2 is 2 layers and 3 is for 3 layers.