The Ortlieb Twin-City Urban is a fully waterproof, compact rear pannier. Its 9L capacity is the perfect size for light duty around town, capable of carrying a jacket, packed lunch, keys, phone, and wallet. The Twin-City comes with Ortlieb's QL2.1 attachment system. Because the bag closes by way of a top flap that folds either direction over the side, the hardware can easily be hidden and prevented from jabbing the user when the bag is slung over a shoulder. The flap zips at the top, then folds over, then has an aluminum clasp that can insert into one of two loops on either the front or back of the bag. The interior is a single compartment with four pockets, two of which are roughly postcard-sized and two of which are slightly smaller. On one of the smaller pockets there is a series of loops for clipping keys or a lanyard. Included with the pannier is an adjustable, integrated shoulder strap. The front side of the bag has an exterior zippered pocket for quicker access to some items.