I actually lost this once I bought it so I didn’t manage to use it for a few weeks/months but I did find it in the end and I’m wearing it right now. The luminosity is not very bright at all, when I go to bed and it’s very dark, THEN it is noticeable but as I said not very bright. Any other time you wouldn’t know that it was luminous. If you’re wearing a long sleeve shirt and try and peak down your sleeve to see it for example, it just looks a weird white colour, no light. As for fit it’s just like all the rest I’ve bought, fit no problem. And for the price it’s worth it anyway. If you see picture/ video you can see that over time the ‘face’ side actually discolours.