Hi Charles,
ZBS, Zelezno Brodske Sklo.
Whilst many were designed by Jaroslav Brychta, from @ around 1931 onward, few were actually made by him.
With this label, this is post-war, and with the oval label possibly 1980s, as the original ZBS label was a different shape, I believe. Yours is definitely before 1992.
These are, as far as I am aware, still in production.
Regards,
Marcus