The hook-and-loop saddle attachment keeps the bag firmly connected to your bike. The low-profile seatpost attachment prevents the bag from swinging while riding. Internal pockets securely hold credit cards and valuables. The loop on the front of the bag easily attaches clips for rear lights. A zipped expansion area allows for extra storage space. The light and robust material holds up to elements without contaminating contents. 1.7-litre (105 cu in) capacity - 2.23-litre (142 cu in) capacity when expanded.