Solid concept and good implementation! [SEP] I love the idea of having something like this that does not require pre-planning on my end, like microwaving or heating, which I always, invariably don't do. I have 3 different masks requiring that type of minimal effort that I have never used. And I love the idea of disposable, something I can take with me when I travel but don't need to worry about bringing back.<br />This activates on its own, as you can see from the box, packaging instructions. I am guessing it just gets activated when exposed to air or when taken out?! All I know it started to heat up within a few seconds of being taken out.<br />It's super light and compact. Which lends to one small disadvantage of not staying on, there is no weight that pushes it on. I just used it with my sleeping eyemask and that applied the exact amount of pressure I would like.<br />The thing I couldn't figure out, it might be a specific batch flaw or I might've not been able to figure it out, was where and how to affix it to the ears, the packaging seemed to imply there are things you could pull but I couldn't find any.<br />Other than that, I found the intensity of heat to be great. It's not too hot, especially for sensitive skin, and especially for a sensitive area like the eyes, and it lasts a good amount of time that I managed to squeeze in, quite nicely, some meditation!