X-10 & X-5 Octopus The emergency regulator according to SeacX-10 Pro Octo, X-5 Octo and Octo Synchro: Seac proposes solutions for a reliable and long-lasting emergency second stage that allows natural effortless breathing. Even if the specs differ, the common denominator is always maximum functionality. Octo Synchro material: ultralight technopolymers X-10 Octo material: technopolymers, elastomers and ultralight alloys (Hi-Flex hose included) X-5 Octo material: technopolymers, elastomers (Hi-Flex hose included)