I went to REI looking for a narrow pack that wouldn't get in the way when hiking through narrow slots between boulders or around trees but would still hold all my climbing gear(i.e. harness, rope, trad rack). Well luckily REI recently came out with the Catalyst and it does all that and more. It is very, very adjustable from when it is nearly empty and you tighten all the straps down or fill it to the brim and hang stuff all over the outside you can still get it to hug you body and be comfortable. The pockets on the waiste belt are very handy for a knife, keys or food. The gear loops are also great for any weird things that us climbers can come up with to clip to them. I'm just really stoked on the versatility of this pack and there's no beating the price for a pack of this caliber.