Birthing Stages Trainer, contents: 6 birth stage inserts, Safety plate with 4 screws (for the optional insert in birth simulator P90), Lubricant, Carry bag, The inserts look the same from the outside, using a number code on the back, the condition of the cervix on the inside
Bonding and Structure Model Set, Immense help when learning organic chemistry, Has some very unique features, Among the 220 durable plastic components, there are a large variety of atom models with different orbital hybridizations, Has flexible and rigid links