AuYou Unique Easy Install Wireless Doorbell, IP44 Waterproof Plug-in Touching Door Bells with 1 Receiver and 2 Transmiter Operating at over 500-feet Range by 52 Melodies Chimes White 2016 Fashion and elegant design doorbell touching buttons. ABS material attributes of high rigidity which is also anti-burn and impact resistance. IP44 Waterproof / Dustproof touch button over 500 FT operating range (1000 FT open area); Wireless range depends on construction and materials. 52 classical melodies: Built-in stereo music, 52 elegant music or custom music (OEM), 4 levels adjustable from 25db to 110db, special high fidelity music chords, selected from the world classical music. Easy installation, the doorbell chime plugin receiver no need battery and mounted very easy; Plug the reseiver into a standard plug socket, then it works; CEFCCROHS certified. Package contents: AuYou Doorbell Chimes x 2; Button x 1; Battery 12V 23A x 1; Screws x 2; Anchors x 2; Double-side sticker x 1; User Manual x 1.