Bought these as we were off on a family holiday, leaving the house empty for a month, and last time we left the house we were burgled!
Whilst we were on holiday I had a phone call from my eldest daughter. Her friend had been past the house and seen lights on so called my daughter to see if she was at our house, she worried that there had been someone in the house so called me. Her friend had also told her that the light had gone out a short while later too. As soon as she told me what time this had occurred I told her not to worry, that the kitchen light had been set to come on at that time!
My neighbour who was keeping her eye on the house had a list of times that the lights were due on and off so she could differentiate whether there was an intuder. Apparently people were still knocking on the door when the lights were on thinking there was someone home, so overall this product did it's exact job and the house was (thankfully) as we left it on our return.
There is usually someone home all the time at our house, so having these timers on lamps were a brilliant precaution for a time when our home was at it's most vunerable. It made us feel much better leaving it.
Would recommend this product, but just know that they can only be used on plug in lighting devices like table/stand alone lamps.