NB: This is bottle nipples only. All other parts must be purchased separately. The nipple is produced from natural rubber latex. Since natural rubber latex is a natural material, color variation may occur. Our bottle nipples come in three different flows: a slow flow, a medium flow and a fast flow. - Round nipple in natural rubber latex - The round nipple matches the nipple from our popular BIBS Colour pacifier - Designed with an anti-colic function The nipple is equipped with an anti-colic valve, that lets out air which reduces air swallowed while feeding. The nipple is produced from natural rubber latex. Since natural rubber latex is a natural material, color variation may occur. Our bottle nipples come in three different flows: a slow flow, a medium flow and a fast flow.