Steinheil Patent Antiplanatic Group lens.
From left: 14 1/8 inches (368 mm.) Cover until 10×12 inches.
10 7/8 inches (270 mm.) cover until 8×10 inches. 9 1/2 inches (240 mm.) cover until 8 1/2 x 6 1/2
A very high quality lens that is little known and used in large format contemporary photography. It is worth rediscovering it