These infrared tactical-grade light sticks have been tested in battle fields and covert operations for decades. ChemLight is the only chemical light brand trusted by the US Armed Forces, and it's not accident. These light sticks provide up to 8 hours of utterly reliable infrared light. Extremely durable, ChemLight is waterproof, non-toxic and non-flammable. The light stick features a hook and gate top which keeps the light source secure whether you're hanging, attaching or stringing them together. To activate the light stick, simply bend, snap and shake. Each IR light stick measures 6'' long, and there are 10 sticks per pack. ChemLights are individually foil-wrapped for protection from light and moisture, guaranteeing 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.