This is an OPPO Li-ion Polymer Battery for the OPPO A3s mobile phone, as indicated by the printed details on the label.
The key specifications visible on the battery label are:
Model: BLP673
Battery Type: Li-ion Polymer Battery
Rated/Nominal Voltage: 3.85V dc
Limited Charge Voltage: 4.4V dc
Typical Capacity: 4230mAh
Rated Capacity: 4100mAh
Rated Energy: 15.78Wh (based on 4.1Vdc) or 16.28Wh (based on 3.85Vdc)
Manufacturing Date: 2018/09/03 (Visible in one image)
Standard: Meets IS 16046/IEC 62133 safety standards (indicated by the 'S' mark).