The Fetus Model Set of 4 is a selection of durable life-like models that allows you to show students and expectant parents how rapidly fetal changes take place during the critical period from 10 to 30 weeks. Made from soft, realistic BIOLIKE 2 material, expectant mothers can easily visualize their little ones growing inside them when they hold these lifelike models representing average fetus sizes at 12 weeks, 16 weeks, 22 weeks, and 30 weeks.