The First Lite Boundary Stormtight Pant is the weatherproof, lightweight shell component of the First Lite Layering Kit. Using patented 37.5 Technology and the industry's best DWR and lamination, we combined custom constructed fabrics made to First Lite's specifications to create the very best in foul weather pants. The result provides unsurpassed protection against the harshest conditions Mother Nature has to offer. This lightweight 2.5 layer pant features full-length zippers, reinforced knees and cuffs and suspender loops for use with your First Lite suspenders. Paired with either our Vapor or SEAK Jacket, you can feel confident that you will be dry and protected from the harshest conditions you will encounter while forgetting they're in your pack on the way out.
An important note about sizing: Please be aware that the Boundary Stormtight pants are designed to be worn over your Obsidians or Corrugates, thus are a roomy fit.
True to Size: Purchase your normal size to wear over other layers
Completely waterproof (20,000mm) and unsurpassed in breathability (30,000 MVTR)
Compact and extremely lightweight
Exclusive 37.5 fabric uses Active Particle Technology moving perspiration (human signature) to the outside of the garment where it is functionally neutralized
Full length zippers means they can be pulled on and off over your boots, making them very easy and quick to take on and off--less than a minute!
Built-in stretch for complete range of motion
Pressure tested watertight zippers on all enclosures
- 37.5™ Technology
- Sizing Chart
More Breathability Means You Stay Drier than the Competition
When First Lite engineered their Outerwear Collection, they looked closely at every fabric technology in existence. Having the pick of the litter, from better-known outerwear technologies to more niche, lesser marketed performance fabrics. The truth in outerwear manufacturing is that the brand in question can generally use whichever fabric they choose. The costs vary as does the performance, but if a brand is willing to pay for the best, they can choose to incorporate it into their offerings. First Lite chose 37.5 because third party empirical testing as well as extensive field use their our own employees left them greatly impressed by the superior performance of the fabric. The bottom line is that 37.5 breathes at a rate that is anywhere from 50% to 300% better than any of its competition, while offering waterproof levels that were within a 5% tolerance of our competition.
First Lite's DNA is active, extremely vigorous mountain hunting. Based in the Rocky Mountains and literally testing products year round in some of the steepest, most demanding terrain in North America. Breathability becomes paramount when you're climbing significantly steep, rugged slopes with heavy packs in less than ideal weather conditions. If you sweat under your outerwear and the fabric doesn't allow that moisture to escape, you might as well expose your base layers to the elements and skip the outerwear all together. 37.5 technology does the absolute best job of transporting that moisture from your base layers to the outside of the First Lite garment so that you can remain safe and dry while exerting yourself in the most brutal of weather conditions. This is why First Lite selected 37.5 Technology over other fabrics and has enjoyed award-winning products ever since.
The Science behind 37.5 Technology
Comfort in clothing is greatly influenced by the temperature and humidity next to skin known as the microclimate. For the average person, the body strives to maintain an ideal core body temperature of 37.5° C. You are most comfortable when the microclimate next to your skin has a relative humidity close to 37.5%. When you are in this ideal 37.5 comfort zone, you are also in your ideal performance zone. 37.5 technology helps your body manage the moisture in your microclimate to keep you in this “37.5 zone” of comfort and performance.
Your body already has the ultimate thermo-regulating system. The perspiration vapor that comes off of skin during activity cools the body when working hard. In fact, each gram of evaporated sweat releases 580 calories of stored heat. Unless this water vapor can be removed from the microclimate, it builds up in clothing, footwear, or gloves and creates a clammy and uncomfortable microclimate. 37.5 technology works to enhance the body’s natural cooling mechanism—the body puts out sweat to cool it down, 37.5 technology removes it from the microclimate.
With 37.5 technology, patented active particles permanently embedded at the fiber level capture and release moisture vapor. Not only do these active particles provide 800% more surface area to the fiber, they also provide a unique driving force to remove moisture vapor unlike any other technology. By actively responding to body heat, the active particles use this energy from the body to accelerate the vapor movement and speed up the conversion of liquid to vapor, significantly increasing drying rates. This means the hotter the user gets, the stronger the driving force removing moisture becomes—and the more comfortable the garment remains.
37.5 technology works to keep the optimum relative humidity in your microclimate so your body more efficiently maintains an ideal core temperature, enabling you to perform better, longer. Fabrics made with 37.5 technology dry up to five times faster than similar fabrics, diminishing wet cling. 37.5 technology is made with naturally derived materials so there are no harsh chemicals to irritate your skin. 37.5 active particles are permanently embedded into yarn and will never wash out or degrade.