SadoTech Model G Wireless Doorbell
I've got good news for those who are trying to get by on a budget as this unit from SatoTech will give you a world of versatility at a very reasonable price. To start with, this wireless doorbell has a 500 foot range, making it the longest reaching unit of all, other than the Jacob Jensen one. That 500 feet will extend to 900 feet if you are transmitting in open area. There are also over 50 different ring tones, the most I've seen pre-installed in any unit and with that many, you should be able to find something you like. The chime unit plugs into any electrical outlet, eliminating the need for batteries as well as mounting.