The monitor sensor was defective, when the pin drop down to detect that the gararge door was open does not work 100% of the time. Dissappointed with the product, it was not as reliable as per the reviews online.

Great product. Works at a longer range than I would have expected. Ordered another door sensor since the first one worked great.

The GM-318 seemed to be the perfect solution to our need for monitoring the opening and closing of our two garage doors. Our doors are insulated steel and the lower edge was not wide enough for installation of the sensors, but a 4 inch by 6 inch piece of thin Masonite inserted in the lower steel channel provided a surface large enough to mount the sensors. They were easy to program to the monitor unit after finding a location in the living area nearer to the garage than I wanted. I found the usable range to be only about 25 feet. The most troublesome problem is that since the sensors are located at the floor level on the doors, the signal from the far away door is blocked by the vehicle parked in the near side. When the near side vehicle is absent the units work perfectly. I have to silence the monitor when the near vehicle is present in the garage. A stronger signal is needed which would probably require a higher voltage battery. The option of extending the sensor's antenna to a higher location might solve the problem. Single door installations probably won't have this problem. I also solved the problem of having the door open for extended periods, (washing the cars) by placing a rubber band around the sensor to hold the plunger in the off position. A switch to deactivate the sensor would have been nice for those occasions. Some improvements would make this a teriffic product.

The system works well but the adhesive foam that sticks to the door does not last and it fell. The other alternative to the glue that does not work is to drill the door to instakk with screws is also nt practical if you have a new or steel door

I am using three garage sensors with the monitor. It occasionally works but most of the time one or most of the sensors report incorrectly. Very flaky.

Easy, simple, does the trick.

Last thing I check before turning off the bedroom light. Works great!

Works as advertised. I have not experienced even the minor problems people have reported (where they have to unplug to reset). We are very happy with this purchase.

Smarthome was excellent to deal with, will be ordering other items again. This product however does meet the manufactures description. 20-30' max transmitter reliability. Unfortulate I really wanted this item too.

I may have received a defective product. I tried it in an environment with a detached garage, about 60 feet between transmitter and receiver. The unit stopped communicating at about 50 feet. I might have received a defective unit.