This item is a Big B or Big Derrick steam shovel, crane manufactured by the Brenner Manufacturing Co., St. Louis, MO., in the 1930's or 40's. It is made of pressed steel and features a distinctive blue and yellow body, a tall derrick arm with a red bucket scoop, and rubber lined crawler treads. It measures 18-25" long, 8"wide, and 21"tall. All of the functions on this one operate, although the strings that move them are very old. The derrick body pivots using a gear mechanism that works. The rubber tracks are in very good condition. Overall, it is a very nice piece in clean, excellent condition with a great patina. Please examine the photos. Feel free to contact me with any questions or comments.