~10 oz in a medium; lightweight, highly breathable, fast drying; zippered nylon mesh venting panels on each leg; light duty cordura panels on knees/insteps and seat.
They are very durable and excellent for warm to hot weather hiking. I use them for three season trips, with an Under Armour Cold Geat Base 1 base layer when it gets cold. I have used the same pair for 4 years now, with a lot of off trail abuse, and they are still going strong. Only downside I can think of is that Montane gear is hard to find in the USA.