The first three, the large polartec power grid, you want those large fluffy grids.. you can easily see that in the pics. you want those large fluffy grids that exhaust heat and insulate. It's a miracle textile.
Left to right, Sitka heavyweight (my favorite and most durable, I have a lot of these articles), then a beretta polar power grid (as durable, same polartec powergrid) I picked up somewhere cheap much cheaper than sitka and it's been as or more durable, then a badlands (power grid?), then a KUIU 260, a KUIU strongfleece 280 and lastly a first lite original klamath type from maybe 2018-ish? (early powergrid)
Some hold up over hundreds of washes and get better, mainly the powergrid fleece.. the others compress and lose their ability to work as a base/mid layer or fail to breathe like the polar tec power grid.
I'm fairly sure the cirque lite incorporates the power grid.
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