The main reason I wanted this wireless doorbell is because the mail carrier is not allowed to open the gate to bring our packages to the door. He (or she, depending on the day) has to leave a notice for me to pick it up at the post office. Now I don't have to do that anymore. I guess for most people this wouldn't even be a problem, but with my anxiety it's hard for me to drive the 20 miles to the post office.
Now, I'm not sure how far it is to my gate, but it's a good distance and the doorbell works perfectly. I haven't looked at the manual for this yet, but Aarron said that the button is not weather proof. So in order to use this it would have to be sheltered from the weather. What we did to get around this was to put the button in a plastic bag and attach it to fence.
You can get this on Amazon here .
All in all I really like this wireless doorbell. It works great and at a distance too.
Have a great day!