From the Black Diamond website:
1.5 KG (3 LB 5 OZ)
45 L (2,746 CU IN)
1.4 KG (3 LB 1 OZ)
35 L (2,136 CU IN)
The Revelation keeps your gear organized, protected and riding close to your body, whether your day includes touring or ski mountaineering. For making quick grabs, its modified panel-load design features a back panel zipper. Your shovel and probe stow separately in their own quick access pockets and the exterior attachment points for skis, ice tools, crampons and helmet are simple yet dependable. To comfortably handle large loads, it uses a Y-rod aluminum stay and thermoformed back panel, waistbelt and shoulder straps.
From the Black Diamond Website:
Y-Rod Our unique Y-Rod aluminum stay, with no welded points, provides support where needed, yet enough flexibility to give total freedom of movement. Cut and bent from aluminum rod stock, the Y-Rod offers a better strength-to-weight ratio than more common aluminum pack stays.
SilNylon Our SilNylon is silicone and PU-coated nylon—a unique material with a high strength-to-weight ratio, water-shedding capability and the ability to self-heal small punctures. SilNylon is used throughout our pack line for its light weight and excellent strength.
Ergo-molded Suspension Ergo-molded foam back panels, waistbelts and shoulder straps are anatomically shaped to eliminate pressure points while transferring the load evenly over areas of contact. Our ergo-molded suspensions allow for a custom-fit feel with excellent support.
Die Cut Hypalon Two-layer Hypalon accessory loops are incredibly durable and streamlined as opposed to the clutter of traditional webbing accessory loops. Grippy and extremely tough, Hypalon is ideal for attaching ice and snow gear to your pack.
Technical pack for ski mountaineering
Front panel compartment for avy essentials
Unique attachment points for skis, ice tools, crampons and helmet
Y-Rod aluminum stay and thermoform carry system for a stable pack
If you are a mountaineer, you can respect the enginuity of this pack. Crampon patch and/or helmet holder, ski straps, large back pocket with holes for avi probes and room for a shovel, clamshell design for easy access, a zipper in the backpanel for easy internal access, dual ice axe sleeves... the list goes on.
I got this pack for quick winter mountaineering trips and canyoneering. If you're one of those people who like a "spot" for everything, this pack has it covered. With the aluminum Y frame, you can haul large amounts of gear (read "TRAD RACK") without a problem. The hydration pouch is a bonus, and there are even two water-bottle like holders on the inside of the pack, along with an internal top pouch for all your necessities like glasses, etc.
The only complaints I have about this pack is the material on the inside, specifically the hydration sleeve, started to wear down as soon as I started using it. Also, the quick access zipper on the side of the pack that touches your back can sometimes jut into your back if you overload your hydration pouch and/or have something pushing on that portion of your pack. In all instances where this has happened, a simple shifting of the contents on the inside of the pack has adjusted the zipper so it's not touching and/or jabbing into my back. Lastly, I don't do ski mountaineering, but a friend of mine who does stated that the side straps (ski straps) don't hold his skis as securely as he would have liked. I have no experience with this, as I have only used the side straps for holding ropes (for which they work fine).
Overall, if I were to have only one backpack, this would be the pack I would choose. It's reasonably lightweight (for the 45L pack it's 3lb 5oz) and has lots of extras that make it really unique and easy to attach multiple objects. Of all my backpacks, this is my "Go To" pack, which can basically cover all my needs. Highly Recommended!