John , I had a friend that got out of knapping so I bought all of his tools and rock. I am not real sure of some of the materials. The bopper I showed is 9" curved and fits the hand well, I believe it was a small moose antler or maybe a tine, I also got a big moose bopper probably 7" long and lg. 2-1/2" dia. and straight, this one was close to the skull plate, One a side note, I learned today to not to swing quite as fast as my copper and let the antler mass do the work. I need to make a antler tine Ishi stick. I'm having fun and trying to learn the differences. Bob