RATING OF ZERO IF POSSIBLE--I HAD TO BUY ANOTHER SET TO HOPEFULLY HAVE AT LEAST ONE SOUND OFF---MANY TIMES NEITHER SOUNDS OFF FOR CARS COMING OR GOING. THIS IS THE WORST PRODUCT I HAVE EVER BOUGHT.

In order to use this product beyond 100 feet, the transmitter antenna on the sensor needs to be replaced with a LONGER wire.
If you have some DIY electronics skills, this may be an option for you instead of returning the unit to the store.

1) Open the base unit by removing the screws and remove the longer antenna wire by unplugging it from the circuit board.
2) Open the transmitter sensor and remove the shorter (6.5 inch) antenna.
3) Make another antenna of the same length as that of the LONGER antenna removed from the base unit. Use similar wire. I reused the connector from the transmitter sensor antenna by cutting it off the old short antenna.
4) Install the new longer antenna into the transmitter sensor.
5) Re-assemble both transmitter and base unit

My base unit can now be located where I want it in the house instead of next to a window.

I hope this helps someone who found this device a bit frustrating and limited.

I had tried 2 other cheaper sensors before buying this one. Here are a few things I wish I had known before buying it:

1. The sound to alert you when the sensor is tripped is very quiet, you would be lucky to hear it with the TV on. It does have a place for you to hook in another devise such as a door bell to make a louder sound. I hooked up the door bell just fine but of course this meant spending the money for a bell and wiring it myself.

2. The 900' range on this must have been tested on the beach. The item struggled to be successful at a little over 100' with no obstacles between the sensor and the base unit except for the wall of my house.

3. The customer service that Chamberlain provided over the phone was excellent. The did help me to get the sensor to work for my purposes but as far as it working to the advertised specifications even they would admit that 900' was a stretch.

Thus far it has produced no false alarms like cheaper ones and after finally adjusting the sensor it has tripped for every vehicle and even for some stray dogs that were trying to dig under the gate! It takes some time to get it right but for me it was worth it to have a reliable driveway sensor.

Purchased this product as a replacement for the REPORTER driveway alarm. The batteries leaked and distroyed the insides. This alarm appeared to be the same other than the name. Looks the same and everything. I got the alarm and installed it in the same place as the other one but I couldn't get it to work. The sensor is about 400 feet from the base. I could only get the alarm to sound when I moved it to closer then 200 feet. Returned it the next day. Going back the the REPORTER brand.

Claims of 900 feet are completely and utterly overblown for real world applications. I couldn't get 40 feet of reception with the receiver inside the house. Perhaps if I put the receiver in direct line of sight outdoors I could have gotten better reception, but gee, then I wouldn't be able to hear the buzzer! Very cheap construction, no seal on the outdoor sending unit, etcetera etcetera. I wasted about 2 hours today trying to get it to work and then giving up and trying to stuff it back in the box. Grrrrr! I'm going to try the Dakota at twice the price...