Apart from the initial purchase price advantage they work out very, very cheap on cost-per-wear. We have had feedback from parents who have put our standard cotton nappies through four babies and then sold them on.
They are built to last in this throw away age.
Size 1 fits babies from around 3kgs - 9kgs which is generally the age range newborn to nine months.
The size 2 fits babies from around 9kgs -17kgs which should fit babies from about seven months to toilet training.
Littlelamb nappies are also available in size 3 which fits from 17kgs+. We sell very few size 3's as most babies are dry before they need them.