Built-in Batttery. Rechargeable dog trimmer with built-in battery is good for exceptional flexibility. It can also be used when charging so you don't have to worry that it will stop working and have half groomed dog. Safe and Sharp Blade. Upgrade stainless steel fixed blade and ceramic moving blade can provide excellent cutting performance. The blade sharp enough for a long time using. Detachable blades,easy to change and clean. Low vibration and ultra quiet design.The noise when working is only about 50 db, to help the pet feel at ease, not afraid cut hair any more. 6 guard combs(3mm/6mm/9mm/12mm/15mm/18mm). The adjustable clipping comb is applicable for clipping hair of different lengths; and the detachable guide combs make for quick, easy comb changes and increased versatility. Please Note: if your pets get long and thick hair, you need to use scissors cut shorter at first, otherwise the clippers may jam up and don't work properly.