I'm sure that at some point you've knelt on the floor in some firehouse annex or church basement learning the fundamentals of rescue breathing with one of these.
And when you take EMT class, you are invariably faced with the Bag 'o Babies:
If you are especially lucky, you have the model for 'emergency childbirth' demos, complete with a rubberized vagina and a palpable fetus and a removable placenta that looks just like a grape fruit roll-up. I had the good fortune of sitting directly in front of the training pelvis for one whole evening while it was parked on the table in front of my regular seat. You'll just have to take my word for it; it was creepy. I can't find a picture and to be honest I am scared to try harder.
All I can say is, if Pennsylvania EMS protocols ever necessitate the use of THIS training item, I quit.