There are two options with this 20" Ishi Stick, a 3/4 " dia. and a 7/8" dia. You are purchasing a 7/8" dia. sitck. These Ishi sticks are made from Delrin, the material preferred by flint knappers worldwide. This is the deluxe design which has a built in allen key storage in the tail end. Simply pull the key, adjust set screws, and push it back into the tool. Never search your toolbox for that elusive allen key again!