This invention relates to a cistem (1010): More specifically, the invention relates primarily to concealed cisterns for toilets having integrated, and preferably adjustable, dual-flushing and odour extraction capability. The cistem (1010) includes a primary chamber (1020) for storing a volume of liquid, a liquid inlet (1026) for the primary chamber (1020) of the cistem (1010) with liquid, an air outlet (1028) for exhausting air from the primary chamber (1020) of the cistem (1010) operatively during filling; and a liquid outlet (30) through which liquid operatively stowed in the primary chamber (1020) of the cistem is dischargeable. The cistem (1010) further includes a fill valve for controlling liquid supply into the primary chamber from the liquid inlet (1026) and a flush valve (60) for controlling flow through the liquid outlet (30). The flush valve (60) comprises of a flush valve seat and a flush plug (1064) being moveable relative to the flush valve seat between an open position, wherein the flush plug (1064) is displaced from the flush valve seat thereby to open the liquid outlet (30) and enable the liquid in the primary chamber (1020) to discharge there through during flushing, and a closed position, wherein the flush plug (1064) is seated on the flush valve seat thereby to close the liquid outlet (30) and prevent the passage of liquid there through. The cistern (1010) also includes at least one actuator (1070) for actuating displacement of the flush plug (1064) from the closed position to the open position, and a controller (1123) for controlling one or more of a group of flushing conditions including: (i) flush type, wherein the cistem (1010) is adjustable between a single flush, dual-flush, on-demand flush or a combination of such flush type conditions; and (ii) flush time, wherein the time of the displacement of the flush plug (1064) by the actuator (1070) for each flush type condition is adjustable.