Unbrako key vs zeta key

Unbrako key and zeta key both are nouns.

Word	Noun	Adjective	Verb	Adverb
Unbrako key	Yes	No	No	No
zeta key	Yes	No	No	No

As nouns, Unbrako key and zeta key are synonyms defined as:

Other synonyms of Unbrako key include Allen key, hex key, Inbus key, Inbus wrench, Unbrako wrench, zeta wrench.

Unbrako key (noun)	zeta key (noun)
a wrench for Allen screws	a wrench for Allen screws