A leak free component if the back-nut is tightened enough. It is dual flish, has ultra quiet operation, has adjustable flush volumes and can be used in a toilet or cold water storage tank. The cistern doesn;t have to be fitted to an external wall for an external overflow meaning that it is ideal for toilets that are in the middle of a building or cloakrooms etc. If water begins to overflow it will alert the user immediately as the water flow can be seen running into the pan and will cope with at least 30L/min.