This is the heaviest jacket tested but also one of the warmest. It’s filled with two layers of insulation – Columbia’s Omni-Heat synthetic fill and down, with the latter on the outside. The inner layer is reflective to add to the warmth – and to give a very bright sunshine reflecting surface when you open the jacket. You could use it for signalling for help! This insulation proved warm enough for sitting round on the summit of Ben Macdui in freezing weather and a stiff breeze, as it should, given the weight of the jacket. The jacket is longer than most. The hood is warm but there are no drawcords so it does blow off in strong winds. The pockets are cut off by a hipbelt. Whilst the weight and bulk are high the cost is quite low for a jacket with down in it.  The large size is roomy on me and easily fits over a thick fleece.