Wireless Doorbell Plus Intercom System

Weatherproof, wireless doorbell/intercom unit works with its indoor unit in any room within 1000'. Any number of additional outdoor bell/intercom units (sold separately) can be used with the same indoor intercom; get one for the back or side door too; up to two distinct tones per unit. All this without wiring...just batteries! Outdoor unit uses four AA batteries (not included); indoor unit's UL-listed AC adapter plugs into standard household outlet. Mounting hardware included.