Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Defective Item

I purchased this item to safeguard my apartment. It worked fine for the first couple of days then it would stop working (technically the sensors would not be linked to the main unit and I had to re-sync the unit). I tried it out for a couple more days and it stopped working again (once again I had to re-sync the sensors). After the 4th time of doing this I returned the item.