From the website, it says it's 1000µL, or 1/1000 of a lumen. This is barely enough to see by, and the page says the light only has a service life of 10 years. Good in a pinch, but this *will* degrade over time... because it's gonna be the same stuff they use in watches to make the tick marks glow.
You'd have to re-buy one every so often if you're wanting one for a bugout bag. It's like an MRE, but light instead of food.