The Royal Global adjustable barrel features an innovative patented mechanism combining a premium aged grenadilla wood bore with an all new eco-friendly material exclusive to Royal Global. Many years in development, the material is created from mixing grenadilla dust with strong fibers that result in an almost identical density to grenadilla. This process allows Royal Global to reduce manufacturing waste and create a more durable, crack-resistant product that will last for many years. By manufacturing the top section and bore with grenadilla wood and the base with the new ECO material, the Royal Global adjustable barrel maintains a wooden bore that helps achieve the warm, rich, and vibrant tone that many players prefer.
Silver plating --- Focus and Centered sound
24k Gold plating -- Power and Deep sound
Rose Gold plating --- Dark and Mellow sound 
Black Nickel -- Sergio Bosi Signature