There are 3 main version of the device: not isolated, galvanically isolated with external power supply, galvanically isolated with internal power supply.
The device is used for converting and isolating RS-232 serial lines. Conversion options: RS-232 / RS485, or RS-232 /RS422. If requested, the company can manufacture devices for RS-232/TTL conversion, although those are no longer in production. USB connectivity is available if requested.