What happened when Slytech took its 2nd Skin XT protective foam (allowing for multi-directional impact energy dissipation), slimmed it down and also made it more pliable? Flexi was born. This back protector conforms to the movements of your body, providing a crucial line of protection from impacts with snow, rocks, trees, etc., while hardly impeding your movement or bogging you down. Without Flexi, the rock always wins. With Flexi, however, you stand a fighting chance.