Description :  KERUI M525 Wireless Doorbell with Push Button 32 Songs 4 Levels of Adjustable Volume Door Bell Set 433MHz   Features :  Main doorbell be inserted in the indoor plug and button be installed outdoor. Fashion design with build-in antenna. Optional 32 songs. 4 levels of adjustable volume.   Specification :  Wireless learning code: EV1527、 PT2262 Adapter DC: 110V~220V to 9-12V Working Frequency: 433MHz Wireless Receive Distance: 150m (open area) Size:Ring part: 93 x 60 x 22mm; Button: 70 x 44 x 20mm   Package includeds :  1 x KERUI Wireless Doorbell 1 x KERUI Push Button (Battery Includes.)   Details pictures :