The Rago Fabrication Toyota Bedrail Flag Holder will hold any flag pole that is 1" or under and is secured with a set screw to ensure your flag flies safely. It is made CAD designed and is made with 3/16" steel plate and 1-1/4" DOM. IThe flag pole holder is made in the USA by Rago Fabrication and is powdered coated for extra durability.
What is it made of? To perfect you could also add Solar Flag Pole Light. It will have double effectiveness. Firstly you will save energy and you at night your car will be marvellous. Secondly you use regenerable energy and Solar Flag Pole Light are cheaper on https://www.amazon.com/Flagpole-Energy-Battery-Illumunation-Vont/dp/B00YBDA7DC/ . I installed two on my Toyota Tundra and you can't maintain how impenetrable is it now. So, well built advice for your work, add Solar Flag Pole Light