2 pack of nighttime doubler inserts. Our natural bamboo/cotton nighttime doublers have 5 absorbent layers of 70% bamboo & 30% organic cotton for extra absorbency. They work as a doubler when snapped underneath Buttons daytime inserts. Buttons diaper inserts snap right into our diapers covers to avoid shifting. Bamboo/cotton doublers are available in all 3 sizes for your growing baby: – Small fits babies from 7-20 lbs (inserts are 12″ in length) – Large fits babies from 20-35 lbs (inserts are 14″ in length) – X-Large fits babies from 25-40 lbs (inserts are 15″ in length)