O'Neill Men's Reactor USCG VestMedium - Grey O'Neill Men's Reactor USCG Vest - in stock now. Products on Sale Are Discontinued Styles or Colors. Features of the O'Neill Men's Reactor USCG Vest Filter Tech Outer Envelope Closed Cell PVC Marine Foam Segmented Foam Core Anatomical Flex Points Concealed Dual Belt System Quick Release Safety Buckles Heavy Duty Front Zipper Overlock Stitched Expansion Panels.