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 newer 'Twist lock' inlet valve; that requires a 45 degree turn to twist off the connection to see the diaphragm. If you have the 'Twist lock' valve then it is also possible that 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.
This diaphragm/washer has an inner ridge on the underside (see photograph 2). Check your existing diaphragm/washer to ensure yours does too.
Please study all pictures carefully to make sure you are buying the correct washer.
If requiring the older diaphragm/washer which 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 diaphragm then see our SKU FTB323 here.