Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Button light bulb saver miracle

I've used these simple devices for more than twenty years. In fact, I occasionally replace a light bulb in my 20 year old house that hasn't been changed since the house was built and many more are still functioning. The device converts AC to DC and avoids the power surge that eventually causes incandescent bulbs to fail. They also decrease the output of the bulb about 25%. I'm sure light bulb manufacturers hate these things and that may be the reason more people don't even know about them and the reason they are so hard to find.