It was super easy to put together and install on my car. It has a 100lb capacity and I have it full & probably at that capacity. It has only affected my mileage by about 1.2 mpg. I was concerned about quality because of price differences among the high $ cargo box products out there but this box is wonderful & at least $200 cheaper.
https://www.amazon.com/JEGS-90097-Rooftop-Carrier-Capacity/dp/B07DMQQP8Q