PDF filed as a schematic for the Huawei M865C handset, with the name carrying the tokens asecond2 and a misspelled brand. The size matches the Huawei M865C quick start manual in the same collection, so it may be a duplicate user guide rather than a circuit diagram. Open it in any PDF viewer and check the first pages before relying on it. A genuine schematic would let you trace power rails, charging and RF paths, and the model printed under the battery should match.
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 @schematic_mobiles. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.