Siamp Dual Flush Large Button Optima 50

The Siamp Large Optima 50 dual flush button, for use with the Optima 50 dual flush valve. When fitted without collar the button is compatible with lid hole diameters from 39mm to 42mm. Supplied with an optional collar to raise the button from the lid and when fitted with the collar the button is compatible with lid hole diameters from 20mm to 50mm. The button has a diameter of 60mm