A PFD is essential when you're working in rough seas, but the bulky foam can inhibit your ability to move smoothly and get work done quickly. Mustang Survival's Inflatable PFD, on the other hand, is built with Hydrostatic Inflator Technology HIT, which automatically inflates the vest when it is submerged to a depth of four inches, giving you the freedom of movement you need without compromising safety should you go overboard. Rain, splashing, or humidity will not cause the PFD to inflate, but it does feature a manual pull cord that lets you operate the inflation system by hand, should you need to. A clear window lets you easily check the inflator's status and replacement date, too, so you will always be able to ensure that your PFD is in good working order. The mechanism does need to be re armed after deployment, so make sure you are familiar with the procedure before hitting the water. The HIT PFD is meant to be worn for extended periods of time, so Mustang ensured that it's both comfortable and durable. The low profile fit and slim buckled straps keep it riding comfortably on the boat or in the water, and the Glideskin Comfort Collar prevents chafing and is easy to clean. There's a hidden zip pocket to hold your keys, wallet, or ID, SOLAS reflective tape, an included safety whistle, and an attachment for a strobe light to increase visibility in choppy seas. The HIT PFD meets both USCG type II and type V Commercial certifications, and is suitable for any adult over 80 pounds.