The technical requirements for O-ESD hardware are summarized along with review of multiple ESD guns available on the market. Technical specifications of hardware on the market are compared to the specification from IEC61000-4-2 standard.
[Schematics and possible realizations of high-voltage generator for O-ESD](https://o-esd.etf.bg.ac.rs/forgejo/dragan.olcan/O-ESD/raw/branch/main/Documents/O-ESD-02.pdf)