I have the kelvin pants so not exactly the same thing but this isn't about warmth. I love these pants very much. They are soo warm and comfortable but here's why there are 3 stars... the durability of mine are lacking. I've already had them repaired and they ripped on a piece of torn vinyl. I mean they aren't meant to bust brush but I can't even sit down. Other than that they are amazing

Believe the reviews. On our coldest day of 2nd rifle season I threw these on over my Timberline pants while sitting for hours glassing for animals. They worked great adding extra warmth and making a long sit very comfortable. When not needed they easily compressed and were stowed on my pack (top lashing straps). The full length zippers make them easy to get over your hunting boots. Why didn't I have these years ago?!?

These are by far my favorite piece of gear from Sitka. As a hunting guide I spend hours behind the glass. These pants are ideal for sitting and glassing. Once you're ready to move, take them off stuff them in your pack and bust a move. Also great for at camp at the end of the day (almost like your favorite pair of sweat pants). Order them the same size as your regular pants. They are fitted to go over the rest of your layering system.

I am a minimalist alpine style (light and fast) hunter. So when anything that is made with primaloft becomes available it becomes part of the arsenal. I have the first gen. pant and have noticed that the second gen. has reinforced material in wear areas, which is great because out of my own neglect have torn holes in mine. Nonetheless, I would keep paying for these pants because of the endless warmth they have provided me on iceberg mornings and early season bivies. The Kelvin series keeps me light and warm in the mountains of Montana!!!!

It's made to be worn as an outter layer insulation... Absolute must have on my late season hunts spent hours glassing. It kept me comfortably warm. Light weight and very packable. I wear a 32 Regular (med), so I got the Kelvin lite pant in Large to fit over my other pants (timberline or mountain pant) which gives me plenty of room between layers without bunching up.

The Kelvin line functions exactly as intended. It easily rolls up and stuffs in a pack. I only put it on after I have reached my hunting spot which for me is either a shooting house or lock-on. I wear the bottoms under a pair of either 90% pants or stratus pants. The kelvin jacket is worn under the 90%, Jetstream or if extremely cold under the incinerator jacket. I absolutely love the stuff and from mid November through January never go in the field with both pieces in my pack! Use it for what it is intended for and you will too!

Hey David - Appreciate your feedback. Please understand that these are not meant to stalk animals in. These are a packable insulation for when you are glassing or taking a long break or at camp. The focus is more on weight and packability for this purpose. Highly recommend the 90% Pant and layering underneath it if you are looking for a quiet, more insulating pant. It's much quieter and more abrasion resistant for stalks.

The kelvin light pants are a great idea, but are made with the wrong material. These pants are way to noisy for any serious hunter. I will return the pair I purchased.