Specs:

• Size: 18650
  
• Chemistry: IMR
• Nominal Capacity: 2600mAh
  
• Nominal Voltage: 3.7V
  
• Discharge: Max Continuous 40A
  
• Positive: Flat Top
  
• Protected: UNPROTECTED
  
• Rechargeable: Yes
  
• Dimensions: 18mm x 65mm

What's in the box:

• 2 x 18650 Battery