Bought the Exmoor and Lomond jackets recently for an event. Sized up in Exmoor to fit Lomond underneath, but the Exmoor fits fine without the Lomond too, due to the flexible material. Didn't end up needing the Lomond as the Exmoor keeps you super snug, even during subzero night events! I'm not sure how Harrier have achieved breathability AND chill barriers, but they have. I suspect witchcraft. Lomond is also a great bit of kit. A lightweight insulation layer which packs down into it's own bag. It's great for walking, but is also not too bulky for a run in. Both items recommended.