Unprotected, button top.  Price includes storage case!  Batteries are sold individually.

This is Sanyo and Panasonic's and newest high discharge capable 18650 cell, rated for up to 10A continuous discharge.  It is a good compromise between IMR and regular LiCo cells, offering lower internal resistance and higher discharge rate capabilities and higher capacity than IMR.  This is a popular cell for high drain XM-L2 lights because it's lower internal resistance allows these high forward voltage LEDs to remain brighter longer. 

Diameter: 18.7mm
Height: 67mm

Manufacturer Cell Specifications:

• Nominal Capacity: 3500mAh
• Charging Voltage: 4.2v
• Maximum Charge Current: 1375mA (1000mA recommended)
• Recommended Discharge Termination: 2.5v
• Maximum Continuous Discharge Current: 10A

These cells, like all lithium and IMR cells, should not be discharged below 2.5 volts.