Back to Wall, 4.5 litres single flush when used with the appropriate Conceala cistern Product Details Company Name Armitage Shanks Brand Name Profile 21 Model Number S3095 Maximum Flow Rate 4.5 l/min Maximum Volume 4.5 litres Category WC Suites Available In United Kingdom Efficiency Rating Chart Company name:Armitage Shanks Model:S3095 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.