Let’s try to add some clarity to what is called Polartec® Power Wool™.

 
  One that Burton makes (https://www.backdropjournal.com/kit-junkies/burton-ak-baker-power-wool-base-layer-crewneck) has the little squares for the inner and although it stretches it’s not like the lycra one below.
This one is the Power Wool that Polartec shows on their website (https://www.polartec.com/fabrics/base/power-wool)
Mine are https://foxwear.net/2018/06/power-wool-for-shirts/

60% Polyester, 40% Wool

. . . . . . .

  Now the other one I have in black, gray and yellow has lycra in them and they make great tights.
It looks and behaves much like PowerStretch, but with superior wool content! By isolating a merino wool interior and a synthetic fiber exterior Polartec® developed a hybrid fabric with distinct surface features to optimize wicking, breathability, odor resistance and durability. Wool’s natural odor fighting properties are given a boost, and the unpredictability of shrinking and shape loss caused from washing is prevented through the resilience of synthetics. Polartec® Power Wool™ adapts to such divergent conditions that it can excel during a wide variety of performance activities and diverse environmental conditions. This performance ability to balance both breathability and warmth provides consistent comfort at all times. This soft, stretchy fabric isn’t just the best technical underwear of the outdoor market, it is ideal for shirts and aerobic wear. It outperforms all next-to-skin fabrics on the market because its patented construction has two unique surfaces: the soft inner layer rapidly wicks perspiration away from the body, while the durable outer layer spreads moisture for maximum evaporation. Weight/Yard: 6.8 oz. Contents: 45% Nylon, 40% Wool, 15% Spandex

Bi-component knit Polartec® Power Wool™ with Merino wool next to skin https://foxwear.net/2024/12/wool-tights/