The First Ascent Hyalite Jacket is an insulated soft shell jacket designed for high aerobic activities with lots of stop-and-go such as ice climbing or backcountry skiing. To accommodate this kind of user the Hyalite is not a super warm jacket but one that will keep you warm while on the move or as part of a layering system. The First Ascent Hyalite Jacket uses 60g Primaloft One insulation which is not as warm as your average down puffy but provides a good barrier to the cold while you are moving. Being a soft shell there is built-in breathability. This is optimized by the integrated non-insulated soft shell fabric under the arms which use 8.9 oz 50-denier stretch fabric so it lets the heat out where you generate it most.

Plenty more to read about in the full review over here.