Lightly insulated so it stands up to cool weather on its own, we made sure all three layers of the Rion Vest—outer shell, lining and insulation—have built-in stretch. The result is an elevated layering staple that moves with you like none other. Rion StretchShell Insulated Gilet Men's Rion StretchShell Insulated Vest in Black, Size: XS by Ariat