These tactical-grade light sticks aren't some child's toy you find at a party store. The infrared chemical lights are the trusted tools of tactical operators around the globe. In fact, ChemLights are standard issue equipment for the US Armed Forces. These ChemLights provide 3 hours of 360 degree infrared light. ChemLight is waterproof, non-toxic and non-flammable. Each light stick has a hook and gate top which keeps the ChemLight secure whether you're hanging, attaching or stringing them together. To activate, simply bend, snap and shake. These ChemLights measure 6'' long, and there are 10 sticks per pack. Each light stick is individually foil-wrapped for protection from light and moisture and boasts a four-year shelf life from date of manufacture. ChemLight meets Defense Logistics Agency (DLA) and NATO Maintenance and Supply Agency (NAMSA) specifications. National/NATO Stock Numbers (NSN) are printed on each product for reference.