... top style: Plain/non-protuberant rectangular keys, with laser engraved and etched and raised braille on keys are available- Waterproof, dustproof, shake ... USB, RS232 Interface options ;- O/S: Ps2/rs232: Win nt4,98se,98me,2000, XP USB: Win 98se,98me,2000, XP and mac os9/osx.