Blue-White Micro Diaphragm Kit for C2 Pump
This item is highlighted as # 9 on the product illustration at the bottom right.
View a picture of the C2 pump this item goes with by clicking the thumbnail on the left.
This micro diaphragm kit, from Blue-White Industries, is part # 72000-551 and is a replacement item that goes with the C2 diaphragm pump.