Cambond via Amazon offers the Cambond Wireless Waterproof LED Door Bell in White for $21.99. Coupon code "MFAWWMEK" cuts it to $18.99. With free shipping for Prime members, that's $18 off and the lowest price we could find. (We saw it in black for $2 less in September.) It features two receivers (each with a range of 500 feet), 58 ringtones, and four volume levels. Deal ends November 26.