Sigelei KAOS Z 200W Box Mod features a complete design overhaul with transparent side panels and new LED lighting features. It features a Sigelei manufactured microchip that monitors your vape output better than before. The improvements within this new unit are plenty, from better ohm readouts, accurate output, and even better use of the amps of your 18650s. To date this is the best box mod ever released from Sigelei. Durable, visually stunning, and an even better value than its predecessor.