Coverking's Hybrid Car Cover combines the qualities of two very different fabrics in one cover. A dense 300D, reflective, water-resistant fabric for the top panels where it repels hazards that come from above, such as damaging UV rays, precipitation, bird droppings, leaves, and more. On the sides, you'll find a lighter weight, breathable fabric that will still protect, but optimally expel moisture and heat from inside - preventing rust and mildew.