This is the Mares Dual Octo with Superflex Hose for Scuba Diving Features: Compact-Size Octopus w/Stylish Design Strengthened by Technology to Give Steady, Natural & Effortless Breathing Lightweight Techno Polymer Housing Hi-Viz Yellow Purge Button & Hose Compact Exhaust Tee: Superior Hydrodynamic Performance & Reduced Exhalation Resistance Vortex Assist Design (V.A.D.) System Hose: 3/8 Thread High Flow Superflex 39.4" (100 cm) Bright Yellow Hose Surpassed Tests Required by EN250 Soft Hypoallergenic Silicone Mouthpiece Dependable Downstream Valve Design Weight: 12.6 oz. (357 g), w/Hose This lightweight Mares Dual Octopus is made of techno-polymer features an oversized silicone purge button so that the purge button is easy to push. All Mares second stages are a reliable downstream valve design and offer the unique patented Vortex Assisted Design (VAD) system. The air bypass tube conveys air to the mouthpiece creating a swirling vortex with a low-pressure area in the center that keeps the diaphragm down during inhalation, for very sensitive and easy breathing at all depths."