an instrumentality invented for a particular purpose

a device (trade name Aqua-Lung) that lets divers breathe under water; scuba is an acronym for self-contained underwater breathing apparatus

a breathing device that is placed over the mouth and nose; supplies oxygen from an attached storage tank

a breathing device for administering long-term artificial respiration

a breathing apparatus used for resuscitation by forcing oxygen into the lungs of a person who has undergone asphyxia or arrest of respiration

breathing device consisting of a bent tube fitting into a swimmer's mouth and extending above the surface; allows swimmer to breathe while face down in the water