Instruction: Given a question and its related document, determine if the question is answerable by analyzing the information in the document. Output yes if the document addresses the question, or no otherwise.

Input:
Question: Is this a stand-alone NG detector or must it be used with some kind of a main alarm system?  I ask because the description says:  "Alarm Output: relay output/sound & flash alarm; RF 315MHz Radio Distance: l00m in open area (wireless type)"Thanks.
Document: Purchased this item with intentions of connecting to alarm system based on description but the version that I got did not have the ability to do this. The instructions were poorly written and did not correspond well with the unit. Was able to modify unit to provide the capability I needed but I clearly did not receive what was advertised.
I read the reviews about these things not working at all but based on the cost I decided to take a gamble. True to the reviews it did not work at all. I mean at all. I opened the box, read the instructions, plugged it in, and nothing. I have a natural gas stove and even went as far as to place it on the unlit stove with the gas on high. The smell drove me and the dog out of the kitchen but not a sound from the detector.
Gave this detector a try due to recognizing the Bestek name and finding most other units costing a lot in comparison. Ordered 2 units, they arrive in timely manor. Plugged both units in and tested by allowing a small brief leak to occur on my LPG range . Both units alarm properly as listed for LPG. Enjoy the outside indicators to tell you if the unit has power and is in an alarmed state or normal condition.
Ordered this because my old house has some very old gas pipes below - Now I am confident that if they start to leak we will know immediately. This for a very reasonable price . I tested the unit with propane and it picked that up perfectly as well. I'm going to purchase another one for my utility area. I like the fact that it plugs in so you don't have to replace the batteries.
I got the unit to go off when I put it on my stove with the burner off. I hasn't gone off otherwise.
Nice price, but after I unplugged it once it did not reset and never worked again. The instructions are only partially in English. I tend to be very generous in ratings, but can't be with this.
I gave this unit a five star rating due to its simple set-up and operation. Just select a location and plug the unit in. Done!
Failed after 3 days. The green light began flashing and won't reset. Obviously poor quality and I recommend you avoid this product.
Best priced one on amazon. The box and manual are all written in chinese, so the instructions were difficult for me to read. But I tested it against my natural gas stove. It worked and did what it is suppose to do.
it didn't sense gas at all, but would go off anyway for no reason... I put it right into the gas stream and got no response and then just sitting on the counter it would go off...I had bought it for a friend... anyway, was of no use at all to me.
Answer: no