OBS Engine 100W Kit is the world's first replaceable battery sleeve 21700 box kit. This ergonomic starter kit combines Engine 100W Mod with Engine S Tank to bring an unparalleled e-cigarette experience. The OBS Engine 100W Kit has a zinc alloy frame and a battery sleeve made of resin in different colors. Along with the chassis, you'll find the comfortable oversized firing button, the LED display screen, two up and down adjustment buttons. Type-C port on the side. It feels comfortable to hold and ...