No, these arent some sort of weird, blue AA battery, this is actually a 18650 Lithium Ion Cell. These round high capacity cells have been mainly used in flashlight type applications but with its capability to be used as a drop-in rechargable cell at 3.7V with a capacity of 2600mAh. This is a great battery option for those of you who need a simple to install and replace cell with a lot of juice.
These 18650 Cells have a standard discharge current of 0.2C to a maximum of 1C and can handle about 300 charge cycles.
Dimensions: 65mm x 18.2mm (2.6″ x 0.7″)