BATTERY VAPE-18650

Those are high-performance Vapcell N40 18650 Lithium-ion batteries. They are quite popular in the enthusiast community because they pack a high capacity into a standard 18650 size.
​Based on the image, here is a breakdown of what you're looking at and what you need to know to use them safely:
​Key Specifications
​Model: Vapcell N40 (INR18650)
​Capacity: 4000 mAh (This is very high for an 18650, making it great for long runtimes).
​Voltage: Nominal 3.6V, fully charged 4.2V.
​Discharge Rating: Usually rated for around 10A to 12.5A continuous discharge