4.0 Men's Beast Performance Pant

Regular price $65.00 Sale price$45.50 Save 30%


If you are looking for ultra-warmth, the Beast is for you! These full-length thermal long johns have a smooth face on the outside of the top for easy layering and brushed ultra-high pile sherpa fleece on the inside to trap air. Works great with the Beast Half Zip.


  • Thermoregulation Technology keep you warm and dry
  • Heavy-duty Sherpa inside for maximum warmth
  • UPF Rating 50+
  • All flat seam construction and rib gusset to prevent chafing
  • Comfort waistband for a great fit
  • 31" inseam, ankle-length fit


  • Climasense fiber fusion is designed to regulate your optimal temperature
  • Thermoregulation technology provides comfort through a wide range of temperatures
  • UPF rated for sun protection
  • Odor Control neutralizes sweat and odor
  • Moisture Management moves moisture from the skin to keep you warm and dry


  • Body: 100% Polyester
  • Rib: 90% Polyester, 10% Spandex


Enjoy free U.S. Domestic shipping on all orders above $75

Customer Reviews

Based on 14 reviews
Frost Bite
Disappointing cut

I own a number of different bottoms in xl and 2xl. I trust this brand. Things normally work and fit but these are not cut like the others. 2x runs a little smaller than normal and the rise is way lower in back. I'm sure I'll get to test them out during the long Minnesota winter but so far the mammoth pants are way nicer.

Terence Schild
Exchanged for something else

Sent these back for an exchange and have yet to get the pants that I exchanged for been like 2 weeks

Julian Fodor
Awesome Base layers

I previously had a pair of heavy weight terramar base layers. They either shrank or I expanded. I will go with they shrank. I purchased the 4.0 bottoms and the 4.0 half zip. I was hunting in near zero degree weather including the wind chill. They kept me very warm. The wind didn't get through either. I wish I had bought these sooner. I also purchased the Terramar 2.0 top and bottom. They are much warmer than my regular base layer. I love the way they breathe and are moisture wicking. These are great products and I will definitely purchase more.

james maxwell
Warmer than warm

Hard core warmth in a comfortable package, first class product

Good heavy bottoms

Love the weight & warmth. True to size. Not very stretchy. Top back could stand to be cut higher.

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