The springs on the jaws allow the mouth to operate and the clips on the sides allow the top of the head to open up. It has DS-70 written in three places which I assume was used to identify it as it was being prepared as a specimen. 70 may stand for 1970 and DS for the person's name or the institution it came from. It is 7 1/2" from front to back, 6" tall and 4 across. The item "Real Human Skull Medical/ Dental Teaching/Training" is in sale since Thursday, September 13, 2018.This item is in the category "Business & Industrial\Healthcare, Lab & Dental\Medical, Lab & Dental Supplies\Other Medical, Lab & Dental Supplies". The seller is "chocolatedog" and is located in Fort Defiance, Virginia. This item can be shipped worldwide.