Bestekmall offers the Bestek 3-Piece Wireless Doorbell Kit for $16.23. Coupon code "FORPRO60" cuts it to $6.49. With free shipping, that's the lowest price we could find by $17. The kit contains a plug-in receiver and two push-button transmitters. Features include a wireless range up to 820 feet, 36 chime options, and four volume levels.