【Safety First】 For security reasons, we provide extra 4 door hooks along with Rooftop Cargo Carrier Bag. If using straps that go through the car, water may leak into the car or it may cause some potential safety hazard as inside straps interfere with air bags in case they inflate. 【Fits Most Cars】Whether your vehicle’s roof has side bars, cross bars or is without a roof rack, this roof cargo bag fits any sized car or SUV. With 4 door hooks included and 8 built-in tie straps, installation can be complete just in minutes. Straps can be attached in different combinations to suit your load and roof rack type. 【Waterproof Material】Made of waterproof zipper, anti-tear coated PVC and welded seams to seal out water, this rooftop cargo bag will protect your luggage against dust, rain, snow, wind and sun. Lengthy straps are easily adjustable and can be buckled together to prevent road noise. 【Spacious Roof Bag】The overall size of cargo carrier bag is 44''x34“x17'', providing an extra 15 cubic feet storage space for your car. Pack all you need for your trip or outdoor adventure and it helps to maximize cargo storage. Just enjoy your comfortable and pleasant trip!