What is a diving helmet?

The Helmet Shell is hand laid up glass fiber reinforced thermal setting polyester (fiberglass) with carbon fiber reinforcement at key points for added durability. It is light and highly impact resistant, and provides a heat/cold barrier as well as being an excellent electrical nonconductor. Kirby Morgan has over 50 years experience in composite laminations.

• A Steady Flow Valve provides an additional flow of air into the helmet backup air source for ventilation and defogging.
• B Auxiliary Valve supplies backup breathing gas to the diver.
• C Gas Supply Non-Return Valve is Commercial Rated™ and prevents loss of gas pressure in the event of umbilical damage, preventing a “squeeze”.
• D Neck Dam/Yoke AssemblySecures the helmet to the diver’s head and positively prevents accidental removal. The angled neck dam helps the helmet ride comfortably while workin face down.
• E Low Pressure Plug is removed and replaced by a suit inflation hose when the diver is wearing a dry suit.
• F Communications are either bare wire posts or a waterproof connector.
• G Latch Catch Mechanism locks the neck clamp and yoke in place.
• H Water Exhaust automatically keeps water drained from the helmet.
• I Quad-Valve™ Exhaust System (Patents Pending), The new KMDSI Quad Valve is a superior exhaust system with exceptionally low exhalation resistance that helps to keep the helmet free of contaminants in polluted water. The Quad valve is the first exhaust that isolates the breathing system from the surrounding water with a four valve, low breathing resistance design.
• J SuperFlow Demand Regulator provides adjustable, easy breathing.
• K Nose Block Device allows the diver to block the nose to equalize ears.
• L Silicone Oral Nasal Mask made of a hypo-allergenic silicone material which has a longer work life than latex.

All this information was copied from the manufactures website