LIQUID FORCE MELODY COMP VEST SMALL 2016 Flex-Span Neoprene Fits like a second skin. 38 panel Flex-Architecture design. PVX is our best lightweight, soft, stretchable and flexible high impact flotation foam. Minimal taper and maximum stretch so the Flex can zip up tight without restrictions. Reversible: If the mood strikes you, flip out this vest for a new look!