Crotch walnut, about 5.5". Opening is 1/2", thickness is 3/16" throughout, with the exception of the base. Its closer to 9/32.
Finish is Tung Oil, Buffed, then BriWax.
Thanks for the comments guys. TD, the size was reduced a little bit due to that. I keep my tools sharp, but it still got me. Sometimes even the old Tormek doesn't sharpen them the way the wood wants.