Most umbrellas ive seen that are rated to block any thing are solid like blackout curtains

I cant for the life of me figure out how that part two pieces and a pressure screw go on the umbrella

The only con i found is the hook thats included for hanging items off the ground

This is not the thickest material which bodes well for portability but only time a few hours will tell if it is effective blocking rays and stray blaster shots