Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A small plastic box full of FAIL!

After placing this directly facing the barking offender, with nothing but a straight shot to the location of the large and loud barking dog (~20 feet) the item horribly FAILED to activate at any setting or combination of settings. I tried everything and they only way I could get it to activate was to loudly simulate a bark with my own voice 4 inches from the sensor. I tried different locations as well and I don't think it ever activated while I was home. Silent or audible setting also failed to activate under heavy and loud barking. I would have liked to have known that unless the dog is extremely close to the sensor that this product fails to activave 100% of the time. Do not buy this piece of landfill.