The Camp Air is one of the lightest and most compact full-featured harnesses we have ever seen. If you are obsessed with traveling light in the mountains, it is hard to find a lighter harness.
If you are an alpine rock or ice climber and want the lightest harness that still has gear loops and some support, it is hard to beat this one. It is a specialty harness; you won't wear it to the gym or cragging. But for traveling ultra-light in the mountains, it is hard to beat. If you don't mind a slightly heavier harness that is also more expensive, check out the or the Black Diamond Ozone.