M65 PANT LINER
Perfect for those static situations like sitting around at camp or belaying or glassing while hunting. Would be way too warm for active use unless well below 0° IMO while wearing a base layer and hiking pant/shell.
The m65 pant liner was designed to be buttoned into the m65 pant so they don't exactly have a good waist closure system, just a button with 2 slots of adjustment. I'm going to mod mine with some 550 cord.
Regardless, 10ozs, very warm, lots of room to layer under and I paid around $10 shipped for an unused pair.
Cool added bonus is that since the sides have 5" gaps between the buttons, you can access your pockets without having to remove or unbutton the pants. Also the crotch is open for quick and easy access. Even with the gaps, the pants still add a ton of warmth.