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.- Ultra Quiet: 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.- Adjustable: 4 guard combs (3mm/6mm/9mm/12mm) are included in each set. 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.- Important 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.