The Rebellion has the option to use 20700 or 18650 batteries giving the user a lot of freedom with there preferred battery. All of the contacts are silver plated including the 18650 battery adaptor. The squonk bottle is made from soft silicone, one of the strongest materials at present for squonk bottles and the genius of the refill method is second to none. refill the squonk bottle installed, by filling it with the 15ml silicone which has an ultem adaptor to do so, so, no need to remove the squonk bottle installed. The body of the design is made from aluminium which is cerakoted with strong magnets on the door. The Rebellion also features the iconic Matthew Hagermann Skull logo which looks awesome!