Genuine SIAMP STORM 33A Single Flush Replacement Toilet Outlet Valve. Why replace the whole cistern when you can just replace the flushing mechanism for a fraction of the price? Chrome Effect button comes with optional spacer. Perfect match? If this item is a perfect match for your current flushing valve there is no need to dismantle the cistern! Just simply quarter turn the existing valve out and quarter turn the replacement back in. No need to call an expensive plumber.