The Fatty Grip (contrary to its name) is actually the thinner of the two Thai sticks that we carry.  The name comes from the size of the dowels within the stick, which are roughly twice the size of the dowels in the Gripped Thai stick.  The size of the dowels lends rigidity to the stick, meaning that it has great rebound off of heads and cymbals.  Plus, said dowels provide extended durability.  Both Thai sticks have rubber gripped handles and two control rings on the dowels for articulation control.