The C1 Core Tanker 1.0ml cartridges are very unique in that the housing is constructed of a patented inner glass tube and an outer polycarbonate tube combination. This combination provides the sturdiest of reservoirs while allowing for optimal flavor. Another unique feature is the Vuber patented quartz coil that is used as the heating element. The quartz heats evenly and does not burn the oil, ensuring that the cartridge does not degrade, leak or clog over time. The glass coil allows for only vapor to be filtered through, giving the best quality experience on the market. For the best outcome, it is recommended to use the C1 with thinner viscosity oils. You will get the same experience consistently with the C1. Breaking into the industry with the newest technologies, C1 Core Tanker Cartridges are on their own level. Included is a base mouthpiece with a choice of either a Black ceramic duckbill or a White Ceramic duckbill shape.