This rechargeable battery is used in the Rigid Industires Halo flashlight, but can also be used in any other appropriate device.
In spite of looking similar, this is not a AA battery.
Unlike the older NiMH rechargeable batteries, lithium ion batteries have the advantages of having a very low self-discharge rate, virtually no memory effect, and can be recharged hundreds of times during the life of the battery.
Self-discharge refers to gradual declining power available from rechargeable batteries while they sit on the shelf.
Memory effect refers to the tendency of rechargeable batteries to have a lower total level of power available as they get older.
Neither of these are serious problems with Li-Ion batteries.
• This battery is a model 18650 (or 168A) lithium ion battery, which is both wider and longer than a AA battery
• Uses lithium ion chemistry with a nominal voltage of 3.7V DC