Cigar Oasis Excel electronic humidifier measures and controls the humidity in personal size cigar humidors up to 300 cigar capacity (4 cu. ft.) over long periods of time. Guaranteed to keep your cigars always fresh! Totally unattended, reliable operation, built-in hygrometer, built-in filtration and mold retardant. Water cartridge could last 6 months up to 1 year. Maintains the humidity at 70% or user adjustable humidity. Flat ribbon cable slips through back or side of humidor or AA batteries. Size: 2" x 3.5" x 6". Color: Black and Gray. Rechargeable batter attachment sold separately. Features Micro-USB connections and WiFi Capability.