Givi T511 Waterproof Inner Bag Liner For Trekker Outback 42 Dolomiti 46 Waterproof Liner/Exterior Bag 38 Liters Size 14.2" L x 14.5" W x 9.4" H Roll down closure system to ensure fully waterproof functionality Fits Givi Trekker Outback 42 Liter OBK42A OBK42B OBKN42A OBKN42B and Dolomiti 46 Liter (DLM46A) Top Case It can also be used on the lid of the topcase or seat, fixing it with the included elastic straps