The black rubber gasket with the screen is a seal that prevents leaks once your showerhead is installed. Please be sure the rubber gasket is in place in the showerhead's neck.
For California residents, a white and yellow 1.8GPM flow regulator is also included to maintain compliance with California Building Code requirements. Place this piece yellow-side-down inside the showerhead, then install the rubber gasket.
We promise, your showerhead is not broken; we just needed to make sure everyone has the parts they need to remain compliant where they live!