PDF datasheet, 80.4 KB, for the SM6T6 series part. The name appears to follow the naming style of surface-mount transient voltage suppressor diodes, but it gives no voltage suffix, manufacturer or revision, so the exact rating must be taken from the tables inside. TVS devices are a frequent cause of shorted rails, and a technician uses the sheet to read breakdown and clamping voltages and choose the right replacement. Any PDF reader opens it; match the device marking code against the table before substituting.
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 @datasheet_technar_org. Enginerys does not host this file.
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The standard format for schematics, block diagrams, power-sequence charts and service manuals.