Ideal for cold to cool surfing conditions, O'Neill's Epic 4/3 Back-Zip Full Wetsuit has FluidFlex Firewall insulation in the chest and back panels to lend extra heat and wick away moisture for improved comfort. Thick UltraFlex neoprene fabric throughout offers plenty of flexibility while we surf. Strategic seamless undersleeve paddle zones also allow unrestricted motion and help eliminate chafing.