Soft and elastic peristaltic plus? nipple (m-sized, cross-cut) allows reproduction of baby's natural sucking motion,magmag all in one set is designed to keep up with your baby's developing drinking pattern simply with a change in the cup top. begin with step 1 (nipple cup), then follow with step 2 (spout cup), and then step 3 (straw cup). the magmag cup promotes the most natural drinking habits and trains your baby to drink liquids in the same way as adults do.