dual flush tank with bottom inle valve with great feature of dual flush. means small buton for sall flush and big button use ore water for flush for solide waste. customer can edjust water level to flush as per his choice to use of water for sall flush and big flush say about 5/10 litter. it outlet valve ade of abs plastic outer body made of poly proplene so light in weight copare to ceramic and very compect also