This is the Mares Octo Abyss Navy Second Stage Scuba Diving Octopus Features: VAD system Mesh grid Fluoropolymer resin finish Rubber hose Extremely cold water use Material: Metal Technology Lightweight yoke: Yes The Mares Abyss Navy Octopus is a full metal housing second stage finished in a stylish black finish and is designed to be pair with the Mares Abyss 22 Navy II Regulator. The metal housing gives the octopus excellent cold water performance and thermal conductivity characteristics. The octopus features a mesh grid front cover that helps to eliminate the effects that strong currents can have on the diaphragm including valve flutter and freeflows. The Mares Vortex Assisted Design (VAD) optimizes gas delivery to the diver by using a bypass tube to route the flow directly to the mouthpiece. The design creates a vortex and subsequent vacuum behind the diaphragm that helps to improve valve response and gas flow rate.