Overall diameter 12.3cm, diameter of inner base approx 7.5cm, edge approx 3cm.
Please note - this listing is for the replacement diaphragm only - if you wish to purchase the Hand Bilge Pump this is listed separately.
Please note - this diaphragm is not suitable for all bilge pumps - please remove your diaphragm and take measurements before ordering (the dimensions are given above and also in the photos). Please do not purchase and then request a return with the reason 'it doesn't fit' as unfortunately, returns will not be accepted on this item. Thank you.