Byron 779 Bedrade Deurbel WitChime Features: This electro mechanical doorbell creates a "ding" or "ding dong" soundThis classic door chime can be wall mounted. With a dual chime facility for front back door recognition. In the Box: Classic Doorbell, fixing pack and instruction manual. Classic doorbell, fixing pack and instruction manual. . This electro mechanical doorbell creates a "ding" or "ding dong" sound This classic door chime can be wall mounted Simple 2 wire installation