This Hypro D252 Diaphragm and Valve Repair Kit (D252REPAIRKIT) is the most complete repair kit you will find for the Hypro D252 Diaphragm Pump. It is a combination of all three D252 Repair Kits from Hypro: the 9910-KIT1723 Diaphragm Kit, 9910-KIT2408 Valve Kit, and 9910-KIT2409 O-Ring Kit. If you notice your pump's performance is starting to wane, then it may be time for a repair. Replace the diaphragms every 3 months or 500 hours of use and replace the valves and o-rings every 6 months or 1000 hours if your pump is in constant use. The Hypro D252 Diaphragm and Valve Repair Kit (D252REPAIRKIT) includes the following.