The Cigar Oasis XL Humidifier automatically regulates and maintains humidity. Battery or outlet powered, it is ideal for low maintenance yet quality humidification. Comes with indicator of low water and low battery. With dimensions of 3.5in x 2in x 6in with AC Power or 2in x 6in x 6in with the Battery Pack, this is a hassel free humidification unit that will fit in most humidors with ease. Provides humidity for up to 400 cigars!.