Nipples are typically made from silicone or natural rubber (latex), while shields are often made from food‑grade polypropylene (PP).
Common suggested age labels include newborn (0+ or 0–6 months), 0–12 months, and 6–18 months. Labels and exact cutoffs vary by brand, so follow the manufacturer's sizing guidance for fit and safety.
Anatomical nipples are curved at the top with an angled tip to match the palate and encourage the tongue to cup around the nipple. This shape helps the baby latch more easily and reduces the effort needed to flatten the nipple.
Common features include BPA‑free and phthalate‑free materials, vented or large‑hole shields to improve airflow, and some nipples with an internal valve that vents air from inside the nipple.
Breastfeeding‑friendly features include a breast‑like curve and skin‑like silicone feel, plus a nipple shape that supports natural latch and tongue placement to mimic the mother's breast.