【Large enough for your family】You can easily put 4 medium suitcases(24" large), 4 sleeping bags, and 2 tents inside. The large space can allow your family (up to 6 persons) to pack the must-haves for a family tour. 【100% Waterproof Design】Our bag is made of 900D PVC Tarpaulin (coated with robber material on both sides), and the zipper with two side waterproof barriers. This design keeps your stuff dry even in rainstorm, by preventing water percolating. 【Anti-Tear Design】By using robber mixed fabric, we improved the bag's performance against the tear force during high speed driving. We not only sew the cloth twice, but also used robber melting method to reinforce the sewing place. 【Convenient】You just need 3 steps. First, put the anti-slip mat on the car top and then the bag. Second, put all luggage inside and zipper it close. Third, tighten the bag on the roof rack, or on the doorframe with 6 hooks if your car has no rack. 【Unique Advantages】1. To perform better in waterproof, we initiated a patent to seal all the stitch pole and cloth seam with robber coating; 2.We put a reflective stripe around our bag to make your car visible enough for a safer trip.