Tesla has always been a reputable and reliable E-Cig manufacturer. Tesla Invader III is a powerful little device with maximum output power of 240W through a voltage diel. Powered by 2 x 18650 (not included). Tesla uses its own chipset to avoid possible inappropriate use of this device (See Features & Specs). Invader III comes with in 3 colors, silver, black and blue. It is a fairly small device considering it holds 2 x 18650 batteries, the size of Invader III is 3.5"(L) x 2"(W) x 0.9"(D). If you want a powerful little device with top quality, this is going to be a no-brainer.