"The bones are a musical instrument (more specifically, a folk instrument) which, at the simplest, consists of a pair of animal bones, or pieces of wood or a similar material. Sections of large rib bones and lower leg bones are the most commonly used true bones, although wooden sticks shaped like the earlier true bones are now more often used." -from Wikipedia
The bones I got are said to be from a cow, although there was no labeling except for price, so I have actually no idea, lets just hope they aren't human. The store clerk was able to play the bones, he told me that it took about 3 weeks of messing around with them before he was able to really get the hang of it. I would post about the store but they seem to be anti-internet as I can not find them listed anywhere.