High Five ceramic inserts are produced from the highest quality premium ceramic available. Ceramic has extremely high thermal stability and retains heat very well. Ceramic is nontoxic and chemically inert ensuring that you experience the purest form of your concentrates. Elevate your DUO experience with one of the inserts that offers superior flavor preservation & vaporization efficiency vs other materials currently being offered. The ceramic insert has a large 16mm diameter bowl to accommodate even the most experienced users.