Now the best at-home hair removal system is even better. The Silk'n Flash&Go Long Life Upgrade Kit is a revolutionary cartridge that is used with the Flash&Go device. The redesigned Flash&Go Long Life kit provides a cartridge with a LIFETIME of flashes. This will be the last cartridge you will EVER need to buy. It will provide users with enough flashes to treat their entire body or any area large or small.WARNING!