2100 mAh capacity, which fits the Samsung Galaxy S5 lithium-ion smartphone battery, model EB-BG800BBE, rated at 2100 mAh, which appears to be designed for the Samsung Galaxy S5
To help you find where to buy a replacement or troubleshoot an issue, could you tell me:
What phone model you are using this battery for?
Whether you need help finding a local store or an online shop?
This will help me give you the exact details you need.