Universal Primer Bulb for Common Fuel Line SizesThe BOAT Gen III Bulb is a universal EPA approved primer bulb designed to fit both 5/16 inch and 3/8 inch fuel line sizes. Its flexible compatibility makes it a practical replacement part for many boating fuel systems. This is a simple dependable option for restoring proper priming function. Universal primer bulb EPA approved design Fits 5/16 inch fuel lines Fits 3/8 inch fuel lines Useful replacement for boat fuel systems