The contract size is 5,000 bushels for oats (~ 86 tons) and the tick size at $ 0.0025 per bushel ($ 12.50 per contract). The contract months are March, May, July, September and December. The last trading day is the business day before the 15th day of the delivery month. The electronic trading hours are 19:00 to 07:45 (at night) and 08:30 to 13:15, according to Chicago time. More information can be found here.
The CBoT (Chicago Board of Trade) is one the oldest financial and commodity futures exchange based in Chicago. In 2007, the CME (Chicago Mercantile Exchange) and CBOT merged to share CME Group Inc.. At the CBOT both e-commerce and via "Open Outcry" is traded on the floor. You can find an overview of agricultural commodity futures here.