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;An extra nylon loop on the face of bag easily attaches rear light clips;Reflective elements enhance visibility for maximum safety in any conditions;Strong and lightweight materials hold up to trail and road grime without contaminating the contents;819 cc (50 cu in) capacity;