An unprecedented reproduction of twelve stages of fetal development. This set makes it possible to carefully study developmental change in small increments of time. From 13 to 40 1/2 weeks of gestation, these fetal skulls demonstrate subtle, but significant changes that are taking place as the human fetus is developing. The set will prove invaluable for biological and medical scrutiny in an attempt to grasp how nature accommodates the needs of the human body as it progresses toward functionality. These skulls are also available individually.nnSpecifications:nnProduct Type: ReplicanProduct Material: High-quality Polyurethane resinnThe following products are included in this set:nnReplica Human Fetal Skull – 13 Weeks (BC-215)nReplica Human Fetal Skull – 17 Weeks (BC-218)nReplica Human Fetal Skull – 20 Weeks (BC-194)nReplica Human Fetal Skull – 21 1/2 Weeks (BC-220)nReplica Human Fetal Skull – 29 Weeks (BC-195)nReplica Human Fetal Skull – 30 Weeks (BC-225)nReplica Human Fetal Skull – 31 Weeks (BC-180)nReplica Human Fetal Skull – 32 Weeks (BC-181)nReplica Human Fetal Skull – 34 Weeks (BC-226)nReplica Human Fetal Skull – 35 Weeks (BC-227)nReplica Human Fetal Skull – 40 Weeks (BC-182)nReplica Human Fetal Skull – 40 1/2 Weeks (BC-228)nnProduct of Bone ClonesnPlease be advised that this product is made to order and will require additional lead time. For further information about the availability and turnaround time of this item, please contact our customer service team at 1-800-659-SKULL.