Magicfly Expandable Wireless Doorbell Chime Kit 1000-feet Range 52 Melodies, No Batteries Required for Receiver(2 Push Remote Button+1 Door Chime) Black Long wireless range--operating at 1000-feet; Laud enough--4 levels adjustable Volume from 25db to 110db; 52 different ring tones--Microcomputer's free selection-son musics and the sound quality is much more better than normal ones in the market; Strong remote signal--can easily penetrate walled barriers; Certifications: All products passed CE, FCC, RoHS approval. <span class="a-text-bold">Certifications</span>: All products passed CE, FCC, RoHS approval. <span class="a-text-bold">Package contents:</span><br> <br> 2 x Transmitter<br> 1 x Receivers<br> 2 x 12V23A battery(10g)<br> 4x screws<br> 4x plastic rings<br> 2 x double-side sticker