Back to Wall, 4.5litres single flush when used with the appropriate Conceala cistern Product Details Company Name Ideal Standard International NV Brand Name New Studio Model Number E8016 Maximum Flow Rate 4.5 l/min Maximum Volume 4.5 litres Category WC Suites Available In United Kingdom Efficiency Rating Chart Company name:Ideal Standard International NV Model:E8016 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.