This is a divider for a 10 Gallon (37.8541 Liter) Aquarium. It measures 11 inches (279.4 mm) height and 9 3/4 inches (247.65 mm) width. This was designed in Solidworks and included the files if you need to modify to fit your own needs. I printed this as one piece on my Artillery Sidewinder X1. It fits pretty well in a standard 10 gallon aquarium when placed in gravel but I may make some clips to hold the top better. There are 3 veio with different hole patter. Enjoy!