The Marucci JB 19 Pro Model is a hand-crafted walnut wooden baseball bat with a 2 1/2 inch barrel diameter and a length of 31 inches. This adult-sized bat features a balanced swing weight and weighs 29 ounces. The JB 19 model is designed for baseball players looking for a high-quality wooden bat with a traditional bone-rubbed finish. It is ideal for players who prefer the feel and performance of a wooden bat in their game.