Rattleware 6 by 5-1/2 by 6 Inch Knock Box New, Heavy Duty design made specifically for commercial use Flat bottoms make it impossible to tip Each box has a replaceable protective rubber bar cover, and an edge gasket made of molded rubber. NOTE: The outer dimensions of 6.75 X 7.25 X 6.25 and with inner dimensions of 5.438 X 6 X 6.25 NOTE: Closed Bottom Knock Box NOTE: Pressure cookers according to all World Standards including UL , ETL etc., rate the capacity based on the total volume after closing the lid