EF series High Frequency Transformer
Applications:
1) Power supply
2) The electric car charger
3) Electrical / Medical / Communication equipments
4) The solar energy & inverter equipments
5) Vehicle electronic equipment industry
6) UPS, VCD/DVD players, audio and visual equipment TV sets,
7) Microcomputer equipment, printers, Terminals
https://www.yozeachina.com/high-frequency-transformer-list/ef-series/ef20-high-frequency-transformer.html