Sounds like army liner pants. Cheap and light. The “matching top” comment further makes me believe it is the army liner jacket. They do run large, so a men’s small probably fits most women.
Some info:
Liner jacket: tinyurl.com/2dfgpk
Liner Pants: snipurl.com/1vhle
If you don’t mind a bit of sewing, you can make a Montbell Thermwrap clone for less than $20 with the above liner jacket. A men’s large comes in at 12oz! Considering a Montbell Thermawrap is $150 and weights 10oz, the cheap way is nice for those on a budget on who need something warm, light and cheap!
Check it out: http://www.whiteblaze.net/forum/showthread.php?t=41034
Paul Mags