Avantek Wireless Doorbell w/ 2x Transmitters $13

Avantek Wireless Doorbell w/ 2x Transmitters $12.99 on Amazon. Shipping is free w/ Prime or on $35+. Product Details from Amazon: 1300-foot range, Simply fix the transmitter on the wall without any wiring; includes 4 screws, 4 anchors, 1 key and 2 double-sided adhesive pads, 52 melodies and 5 adjustable volume levels with a maximum setting of 115 dB; set a different ring tone for each transmitter so that you know exactly which doorbell has been rung