Check the listing for details. Zeagle F8 Octo. Condition: New. Listed at 244.95 USD. Lightweight, high performance with free-flow control, heat sink and adjustable cracking pressureInhalation diaphragm provides superior tear strength and improved response time to breathing (super soft silicone molded over a low friction disk).Improved exhaust valve ensures dryness and a lower exhalation effort.Seat-saving orifice, compliments of Atomic Aquatics, retracts when not in use - extending the life of the breathing tube seat. (#5,803,073)Seat comprised of soft silicone molded over a metal insert to deliver the firmness required for an airtight seal while maintaining the necessary elasticity to prevent leaking.Redesigned front cover and inhalation effort control knob use co-molded components that provide the necessary grip, soft touch and ease of use. Zirconium-plated inlet tube and heat sink for superior corrosion resistance.Redesigned heat sink dramatically increases surface area, aiding in the heat exchange necessary to avoid freeze-up.Co-molded silicone mouthpiece for better fit and less jaw fatigue Second Stage Materials: Cover: TPU Case: Nylon 12 Poppet Seat: 316 SS insert with silicone overmold O-rings: Nitrile Diaphragm: Elastomeric Polymer Exhaust Valve: Silicone