The X Bowl is machined out of a solid piece of aluminum coated in Type II hard anodize which creates a virtually indestructible piece of course backed by Phoenician's lifetime warranty. As a result of the material and construction there is no need to worry about heat retention or metal taste as the X-Bowl functions identically to glass (Please read FAQ about aluminum and anodize for more detailed information). As the name implies, one of the unique features on this piece is the shape of the bowl. This shape allows for controlling the amount of product being ignited; commonly referred to in the industry as cornering. It also incorporates a comfortable concave handle for easy operation. The X-Bowl comes standard with an 18mm taper.