At the back of the cartridge is the Precision Trimmer™ which is ideal for tricky places such as under the nose. It also features an enhanced indicator Lubrastrip which comprises of vitamin E, aloe and natural oils which turns white when your cartridge needs a replacement. Powered by battery the Gillette Fusion Poweer emits micro pulses which enable the razor to glide with minimum friction for an incredible shaving experience. It also features automatic shut off in case of accidental activation and a low battery indicator so you know when to replace the battery. It is safe to use in wet environments.