preserver vs rescue equipment

preserver and rescue equipment both are nouns.

Word	Noun	Adjective	Verb	Adverb
preserver	Yes	No	No	No
rescue equipment	Yes	No	No	No

As nouns, rescue equipment is a hypernym of preserver; that is, rescue equipment is a word with a broader meaning than preserver:

preserver: rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning
rescue equipment: equipment used to rescue passengers in case of emergency

Other hypernyms of preserver include float.

preserver (noun)	rescue equipment (noun)
rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning	equipment used to rescue passengers in case of emergency
a skilled worker who is employed to restore or refinish buildings or antique furniture
someone who keeps safe from harm or danger
a cook who preserves fruits or meat