Technivorm Moccamaster 53054 9-Holes Coffee Outlet Arm, One Size, Silver

Does the 9 hole spray arm work with the Grand 15 cup brewer?

Is there anything I can do about the water spraying arm only spraying one side of the coffee grounds?

What are the dimensions? It says 1/2 inch wide, it must be at least an inch from the photo.

Does this arm include the round rubber gasket that fits in the large hole?