Water-repellent, all-round-double-zippable top-loader main compartment made of recycled PET with a tarp base and tons of details.  Padded compartment for laptops up to 15" and two side compartments for bottles and really fat wallets. G-hook strap for everything with space for a U-lock.  A zippable, quick-access compartment and key holder on the shoulder strap.