The Arc'teryx Men's Beta LT Jacket gives you the lightweight construction you want for fast and light alpine assents without sacrificing any of the weather protection you need for life in the mountains. The LT takes the bombproof AR and slims it down in the weight department. A Gore Tex Pro three layer, fully seam taped shell holds off the worst storm you'll encounter and breathes incredibly well. The LT is made from N40p X shell fabric, which is supple, yet durable. The fit is trim, but with e3D Ergonomic 3 Dimensional patterning, including articulated elbows and gusseted underarms, that enhances your mobility and comfort in tight spots.WaterTight zippers will block out any and all moisture in your wake, and when it gets bad, hide under the helmet compatible, fully adjustable storm hood with a laminated brim and lock down the cuff tabs and hem drawcord. Even with all this protection, the Beta LT Jacket still only weighs 10. 1 ounces, which is less than in years past.