Back to Wall, 6/4 litres dual flush when used with the appropriate Conceala cistern Product Details Company Name Ideal Standard International NV Brand Name Playa Model Number J4683 Maximum Flow Rate 4.5 l/min Maximum Volume 6/4 litres Category WC Suites Available In United Kingdom Efficiency Rating Chart Company name:Ideal Standard International NV Model:J4683 4.5 l/min The average flushing volume for dual flush WC Suites and Cisterns is calculated as (a + (3 × b)) ÷ 4, where a is the full flush value and b is the low flush value.