Having tried many things to help me sleep better, I was dubious about whether this would work, but was reassured by the money back guarantee. This sleep mask is amazing; so comfy, easy to use, and I've found myself sleeping until my alarm rather than my usual 4am wake ups. Absolutely worth every penny. Amazing customer service too; I originally bought the Pro but wasn't keen on having to mess about with my phone at bedtime, so upgraded to the Deluxe as it has the built-in sleep sounds. They got back to me straight away and organised an easy exchange. Would 100% recommend!