Close coupled, 4/2.6 litres dual flush with delayed action fill valve Product Details Company Name Ideal Standard International NV Brand Name Alto Model Number E7543, E7544 Maximum Flow Rate 2.95 litres Maximum Volume 4/2.6 litres Category WC Suites Available In United Kingdom Efficiency Rating Chart Company name:Ideal Standard International NV Model:E7543, E7544 2.95 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.