MGM Fenway Proscenium, Fenway Park, Bostom, MA MGM Fenway Theater chevron proscenium (50' x 100'), replicated in UL 723 and ASTM E-84 Class A fire rated composite polyurea with a brass finish. Left and right outer corner sections in composite polyurea. Fabricated inner and outer left corner sections in polyurea. Right corner outer component with brass finish. Close-up of chevron detail and brass finish. Top section of the upper left corner panel ready to hoist into place. UL 723 and ASTM E-84 Class A rated assembly. Top sections of the right and left corners and center keystone installed on the upper proscenium. Left and upper proscenium sections completed.