Magicfly Expandable Wireless Doorbell Chime Kit 1000-feet Range 52 Melodies, No Batteries Required for Receiver(1 Push Remote Button+2 Door Chime) Black Tunes: different ring tones, over 52 (16 chord) elegant melodies; Volume: 4 levels Volume adjustable from 25db to 110db; Stable long Wireless Range: 200 meters (300 meters at open area); Excellent materials keeps itself from getting higher temperature & interference; Easy installation; convenient; double-side stickers;long lifetime; IP33 Waterproof; It is easy to DIY; A stylish modern design in classic black; Includes 2 plugin receiver unit and 1 remote transmitter button 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> 1 x Transmitter<br> 2 x Receivers<br> 2 x 12V23A battery(16g in total)<br> 2x screws<br> 2x plastic rings<br> 2 x double-side sticker