Diaphragm Kit for AR-252/AR-19, AR North America pumps. Blue Flex 
The kit Includes the piston diaphragms, accumulator diaphragm and the o-rings that seal the pump heads to the main body. If the oil in your diaphragm pump has a milky gray color, you most likely will need to replace the diaphragms. Running a diaphragm pump with oil that is mixed with chemical can cause extensive damage to your pump. Keep this kit handy if your D252 is in constant use. We recommend changing the diaphragms every 3 months or 500 hours of use. 
Includes: Blue Flex 
Qty 2 9910-800085 Piston Diaphragm 
Qty 2 9910-480440 O-Ring 
Qty 1 9910-800190 Accumulator Diaphragm,  
Qty 2 9910-800210 O-Ring