NOTE: There are two very similar washers/diaphragms which are difficult to tell apart from photographs. Ignore the colour of the central pin in your current diaphragm, it is purely incidental as the manufacturer has changed the colour a number of times. PLEASE ENSURE YOU ORDER THE CORRECT ONE FOR YOUR VALVE AS PER ADVICE BELOW;
This diaphragm/washer suits the older model inlet valves with screw caps, often likened to compression joints where you have to unscrew the top to get to the washer
If requiring the newer diaphragm/washer which suits the newer 'Twist lock' inlet valve; that requires a 45 degree turn to twist off the connection to see the diaphragm (possibly your existing old diaphragm has 18 little ridges pressed into the rubber but just to confuse things the replacement diaphragm is no longer manufactured with the ridges) then please go our listing FTB2654 here.