This is a virtually brand new Diving Equipment and Supply Company (DESCO) non-return valve. This is a more modern style valve sold by DESCO today for Mark V helmets and commercial styles. The valve is being sold as is and has not been tested. Part is marked DESCO and also FLOW with an arrow indicating airflow direction Will thread onto any Mark V and most commercial hats. 
 
Price includes shipping within the contiguous United States. Please email for a shipping quote if outside this area.  If you would like more than one item, we can combine shipping. Just email us your request and will provide you with an updated shipping total.