This bat is MLB grade birch model JM8B. 
The JM8 has a 2.60" barrel diameter with a slow taper down to a .95" handle and a traditional knob.  Huge barrel, but even in feel.
 
All In stock bats come in matte finish.
All Clear Handle, Clear Barrel bats come with a black logo and engraving.
All Black Handle, Black Barrel bats come with a gold logo and engraving.