Fulton Street 9/11 Memorial by Underground Signs. This NYC subway signs are just like the ones you see on the platform"from their clean Helvetica type to their aluminum forms. Get an exact replica from your favorite stop, or make your own! Details: .063 Aluminum, the same non-corrosive metal the MTA uses, and coat them with a durable clear laminate. 58 x 12 x 1" Underground Signs loves cities. Modern design, and the systems that unite them. Also making things and sharing them. So Underground Signs started a company just to do that. Now you can bring a piece of city you love into your home.