Octopus - Diving Octopus - is an additional 2nd Stage Regulator which divers carry for there Buddy.
Aqualung having a matching Octopus for each DV (Reg) - Kronos Octopus - has a pneumatically balanced
second stage with Side'X deflector to eject bubbles on just one side, leaving the field of vision clear. Others include Legend Octopus, LX Octopus, Mikron Octopus, Calypso/Titan Octopus
