Hydrostatic Technology Offers Reliable Inflation The Auto Hydrostatic Inflatable Personal Flotation Device (PFD) will only automatically inflate when submerged in 4 or more inches of water and not prematurely due to rain, spray or humidity. Low Maintenance No inflator maintenance is require for 5 years unless the PFD has been inflated. You can easily view the inflator status and replacement date through the safety inspection window. Green indicates ready for use. Designed For Serious Users Made for the most demanding users and the most severe marine environments the Auto Hydrostatic Inflatable PFD is constructed with durable 420-Denier nylon and heavy duty polyurethane coated nylon. It will meet the challenges of even the most demanding users. It also features the patented SecureZip™ closure system. The PFD will stay closed during even the most rigorous activity. It effortlessly opens upon inflation and is easy to repack. Comfortable To Wear Designed to be lightweight and comfortable the PFD can be worn over a T-shirt or jacket. It is low profile and allows for the maximum amount of mobility. The neoprene Comfort Collar™ is so soft it won't chafe your neck. Its so sleek and comfortable you'll forget you are wearing it.