Snap In Bamboo/ Cotton Inserts (6 pk) - Each insert is 5 thirsty layers. The outer layers are a soft and durable blend of 70% bamboo and 30% cotton. The 3 interior layers are extra absorbent Microfiber which is 100% Polyester. We offer these in two contoured sizes. Size 1 is 4.75 inches on the ends, 4 inches across the middle and by 11.75 inches long. This size is suitable for newborns through about 15 pounds. These small sized inserts snap into either the OsoCozy Newborn or One Size Diaper Covers. With this smaller size it is possible to avoid the extra bulk while baby is still small. Size 2 is 5.75 inches on the ends, 4.75 inches across the middle and by 12.75 inches long. It is the typical one size insert. It fits best over 12 pounds but can be used from birth, although it may be slightly bulky for the newborn. The inserts snap into the OsoCozy One Size Diaper Covers. Together with our diaper covers they make a great "All In Two" diapering system.