A frame assembly of an agricultural round baler. The agricultural round baler includes at least one roller and a tail gate. The frame assembly includes a main frame and a pair of frame modules removably connected to the main frame. Each frame module of the pair of frame modules includes at least one roller mount configured for mounting the at least one roller and a tail gate mount configured for mounting the tail gate and defining a pivot axis of the tail gate. The pair of frame modules defines a baler size for producing a correspondingly sized round bale.