This listing is for a Pack of 1 Metro Rapid has an easy to remove upper section allowing easy maintenance and replacement without the need to remove the cistern Flush volumes can be varied between 6,7 and 9 litres making it suitable for replacement installations All siphons come complete with internal overflow,siphon backnut, coupling nut, sealing washer and low level flush pipe seal as standard For internal overflow measure from the cistern to the waterline and add 25mm, ensuring that this measurement is a minimum of 10mm below any aperture in the cistern to decide what height siphon is required for the installation., Manufacturer: Macdee