Archive labelled only A20, a 13.7 MB ZIP with no brand, model code or contents named, so the file name tells very little. It likely relates to a Galaxy A20 phone, but open it and check the documents before relying on them. Packs like this often hold a service manual, schematics or board layouts. Such material helps a technician locate parts, follow charging and power rails, find test points and check part numbers. Match the model code on the device to what the documents cover.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @esquematicosdecelulares. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.