Highly recommended for anyone living in a place that relies heavily on Air Conditioning in the summer. I live in Oman with summer temperatures of 50°C. In order to deal with this the electricity supplier pushes up the voltage to as much as 280v (to reduce current rate). I have had a TV power supply fail and also a desktop PC power supply fail due to this.
This APC device, keeps my electronic equipment at a constant 230v and avoids damage to my expensive devices.