MAV HL PERFORMANCE LAYERING - FOR WHEN YOU DEMAND HIGH WARMTH TO WEIGHT RATIO. The Mav HL Liner is a synthetic insulation jacket that is super-lightweight, super breathable and easy to stow. Engineered from an incredibly light and comfortable face fabric it is both water resistant and windproof. For insulation for sailors we have specified synthetic down as the insulator. Unlike natural down it is water resistant and carries on providing warmth even when wet, additionally it dries quickly too. 1. Super Lightweight with high warmth to weight ratio. 2. Incredibly comfortable to wear due its high breathability. 3. Can be worn as a technical layer or in everyday life as a 3 season jacket.