The S360 Second Stage is a Air-Balanced-Flow-Valve Design with a Techno-Polymer Barrel with a Rugged, Precision Molded Carbon Fiber and Techno-Polymer Case. The Diver Adjustable Venturi Initiated Vacuum Assist (VIVA) Dive/Pre-Dive Control Switch and Extra High Flow Exhaust Valve account for Easy Inhalation & Exhalation at any Depth or Breathing Rate. The Regulator comes equipped with a 3/8" Threaded Super-Flow Hose with Strong and Durable Kevlar Lining and a Super-Comfort High-Flow (HF) Mouthpiece for Smooth Air Delivery. The SCUBAPRO MK11/S360 Regulator weighs 30oz (850g), comes with an Owner's Manual and is covered by a Limited Lifetime Warranty.