Rear Rack Bag with retractable side panniers and rain cover , bicycle rack bag by Biria - Mezano Rear bag compatible with all rear carriers Sides open up to small panniers rain cover included, water bottle holder and Shoulder strap.Dimension: 11.5(L) inch X 7(H) inch X 6.25(W) inch This Bag secures firmly to the rear rack with 2 side Velcro straps and 1 in front and is rock solid.