UF Pro Delta OL 4.0 Tactical Winter JacketTHERMAL INSULATION THAT ACTUALLY WORKS. The Delta OL 4. 0 Tactical Winter Jacket is insulated with G LOFT, a hollow polyester fibre filling that lines the torso and sleeves. Those fibres capture warm air from your body, meaning the jacket needs less bulk to provide superior inner warmth. You can depend on G LOFT to keep you warm and dry even in the worst wet weather because it doesnt absorb moisture. And owing to its high compressibility, the jacket