GROOM ESSENTIALS 2-in-1 Eyebrow and Mustache Trimmer GROOM-GEMS304 Battery Operation: This mens beard trimmer is powered by one AAA battery, thus eliminating the need for one that needs a cable to charge up. This effectively allows you to stay focused and concentrated during trimming sessions without any pesky wires or cords getting in the way. Ergonomic Design: Comfortable and compact, the Groom Essentials Micro Precision Trimmer for Men is easy to hold in your hand. Such a design is especially important when you have to use the trimmer for extended periods of time during your self-care grooming sessions.