This chemical light stick is a game-changer when it comes to facility safety products .After I put it to the test I was amazed by the brightness and duration of the light emitted. It is perfect for emergency SITUATIONS and can be easily spotted from a distance. The fact that it is industrial and scientific grade assures me that it is a reliable product. The only con I can think of is that it is a bit pricey compared to other chemical light sticks in the market..