Suzuki SY413 Service Manual page 5156

S-1B-2 AIR CONDITIONING (OPTIONAL)
1. Compressor label
2. Service valve
GENERAL DESCRIPTION
D Whether the A/C equipped with the vehicle being serviced uses
refrigerant R-134a or R-12 is indicated on the LABEL installed
the compressor.
Also, it can be identified by the shape of the service (charge)
valve.
D The manufacturer, Seiko Seiki or Sanden, can be identified by
the label on the compressor body.