Storz
Symmetrical, sexless coupling used across Germany, much of Europe and many export markets. Sized by DN (DN25–DN150).
Machino / KD
Common in Russia, CIS and parts of Asia (KD/KDK series). Check whether the hose end or the hydrant side is male.
BS 336 (John Morris)
Instantaneous coupling used in the UK, Middle East, India and Commonwealth markets; 2½" (65 mm) is the usual hydrant outlet.
NST / NH
US National Standard Thread used on hydrants and hose in North America; specify thread size and gender.
GOST
Russian standard couplings and hydrant outlets — give the GOST number on your specification.