No, we do not have any flashlights that run on 10440 batteries. If you're interested in keychain flashlights, we recommend you look at the Fenix E03R and E02R rechargeable keychain lights and the Fenix E01 V2 keychain flashlight.
The Fenix E02R includes a built-in 120mAh Li-polymer battery. The battery is unable to be removed and no other batteries may be used.
No, all of our Fenix flashlights have multiple outputs. The light that we have with the fewest number of outputs is the E02R with two outputs. This information may change in the future
Yes, the light may accumulate heat when used on the High output level for longer periods of time. To reduce temperature, the light may automatically step down a few lumens. The high output may be reselected if needed.