Unique 3 layer construction has air pockets on the inside that trap warmth without losing breathability, so it keeps you cool when you’re moving & warm when you’re not Double knit insulation panels are soft but pack incredible warmth 100% Polyester Collar Style: Band Under Armour Women's Storm Daytona Vest Fitted: Next-to-skin without the squeeze Sleeveless Material wicks sweat & dries fast Low profile collar Lycra binding on hem