This is a small commuting & hiking pack that is built to last. Arcteryx have not compromised at all on build quality & fabric strength to provide a super tough & durable versatile pack. The large bellows front pocket is made from a coated nylon Armorlite fabric to withstand heavy wear & tear, whilst the body of the pack is made from a tough basket weave nylon with a PU coating to provide abrasion & water resistance. Access to all areas is via water resistant zips to give you as much wet protection as possible. Twin mesh side pockets & an internal hydration sleeve complete the storage options. A fully padded back panel features ergonomic hip wings for stability & the padded shoulder straps have an adjustable sternum strap & Hypalon fabrics for increased durability at key wear points. An internal back plate can be removed to make the Arro more compressible, & lighter. However this pack is all about strength & durability, so I wouldnt worry too much about the weight & pack size.