Close Coupled, 6/4litres dual flush with conventional fill valve Product Details Company Name Ideal Standard International NV Brand Name White Model Number E0001, E0002 Maximum Flow Rate 4.5 litres Maximum Volume 6/4 litres Category WC Suites Available In United Kingdom Efficiency Rating Chart Company name:Ideal Standard International NV Model:E0001, E0002 4.5 litres 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.