I'd say it's probably a 55 or 75E as I came up with about 48 inches wide. I had the same idea as Sssea's, outlet covers are about 3 inches wide and I measure about 16 outlet covers length wise.
75g Planted Barbs Denison, BlackRuby, Tiger, Albino Tiger, Green Tiger, Cherry, Gold, Checkered, Odessa.
NonBarbs Cardinal, Neon, RummyNose, Bloodfin Tetras, Z. Danios. 1RTS. Amano, Bamboo, Ghost & RCS. 20g Long Shrimp Tank RCS, Tiger, Amano.