This sublime & utterly gorgeous pack is made using Arcteryxs amazing AC² (Advanced Composite) technology. AC² uses a lamination & coating process to create extremely strong, lightweight & highly water resistant fabrics. This process allows Arcteryx to create an almost seamless construction & allows direct placement of components, such as straps, eliminating stitching. This amazing fabric is then turned into product using complex 3D patterning, heat sealed seams & micro seam taping resulting in strength, stability, structure & minimal weight. The result is a featherweight, extremely water resistant & massively tough climbing & ascent pack. The main body of the pack is made using a high denier ripstop nylon that is exceptionally durable with a high tenacity tear strength & coated on both sides with urethane to create an air-permeable fabric that is 100% waterproof. The minimal design of the Alpha 30FL does not include a traditional top pocket closure, instead a canoe bag type closure is used to create an internal watertight seal. An internal roll top secondary collar is bonded to the main pack & seals the contents, this is then protected by a tough nylon ripstop external primary collar with a draw cord closure. These collars can both be extended to provide additional storage. A single lightweight webbing strap clips over the top to secure the load & can be extended to carry ropes. Crampons & ice tools are stored using webbing loops & a simple elastic bungee system that also compresses the load & adds additional external storage. There are no internal stays on the Alpha so the load is supported by a laminated HD 80 high density polyethylene foam that also protects your back from protruding contents. The shoulder straps use a laminated construction of burly double weave nylon & soft edged Hypercell foam to distribute the weight without causing hot spots. Finally a small external zipped pocket with a key clip finishes off this simply stunning high performance & technically advanced pack. AC² Advanced Composite technology Weatherproof Roll Top extension collar adds additional carrying capacity Thermoformed shoulder straps with soft edges 6 integrated front lash points for crampons etc. Twin ice tools attachment system Elasticated compression system External zipped pocket with key clip