This case will allow 2 full-breadboards to be used with the oversized ESP32 dev boards. To make it work you will want to carefully cut away the sticker connecting one of the power rails where two breadboards would normally be connected together. That will leave one power rail between the two full-breadboards. It will also leave 2 pins on one side and 3 pins on the other side for use with the ESP32 dev board. This is a tight fit so it should stay in, but I still take the film off the back so the sticker can ensure the breadboards stay firm into the case.