The mfused vape pens are designed for use with mfused cartridges only. Will not try to use other brands. Carefully twist the cartridge into the threaded stop from the battery until it's securely connected. Do not overtighten. Wiggle USB cable – Be certain cable has a snug relationship to battery https://mfuseddisposablenearme79923.kylieblog.com/30811430/mfused-disposable-blinking-for-dummies