As far as the light pulses are concerned, I can't answer that, but there are 3 essays.

The money-back guarantee is offered by the manufacturer and unfortunately cannot be claimed by us. If you order such a promotional item, the money-back guarantee would have to be handled by Philips. You would have to ask the manufacturer whether the item is eligible for this offer and what the exact procedure would be, as they offer this option. The conditions of participation can also be found at Philips.