These are high quality, rechargeable batteries from Efest that are available in a variety of different sizes and capacities. Every battery comes with a transparent shield case (as shown in picture) to help you protect them while carrying.
 
Please note: This is the price for a single battery

Specifications:
Capacity: 2500mAh
Voltage: 3.7V
Style: Flat top
Protected: No
Size：18650 (18mm diameter x 65mm long)
Type: Li-ion INR (Rechargeable)
 
Safety, storage and disposal
Lithium ion (Li-Ion) Cells can be dangerous if used improperly. By buying Li-ion batteries from us, the buyer assumes all associated risks.
Always use a battery charger that is rated for Li-ion cells
Batteries should never be left charging unattended
Batteries should never be loose in pocket or bag
All lithium batteries have a cycle-life, however a battery should be replaced every 2 years - whichever comes first.
Never continue to use a battery with a broken PVC wrap.
Never completely discharge batteries
Do not expose to extreme heat