TatcoWireless Doorbell, Battery Operated, 1.38 x 0.75 x 3.5, Bone

The distance quoted may be accurate if there is only one wall; it has limitations with 3 walls and two floors! No matter -- it is loud enough I was able to locate it to a spot two floors directly over the button.Only drawback it that there is no easy way to "back-up" to a tone once it is passed. You can only navigate the tones in a single direction! If you find one you like, stop or you have a long effort to move around to it again!

whenever the sun is hot the driveway gives off heat and this thing is constantly going off.

Excellent product with extended range capability. In addition, it is water resistant. I would recommend this over anything else in it's price range.

It is very loud (almost too loud) and works at a good range...but it goes through batteries on a weekly basis without even being used. Waste of money.

There are endless doorbell tones but you need to go through all of them if you passed by one you prefer. None are very pleasant and some are just weird / really long. It was inexpensive so it's really a case of "you get what you pay for." I wish I had shopped around more before I chose this one.