Features: OOTDTY fresh and effective Material: Nitrile rubber,Features: dependable sealing and growing old resistance. Pressure diaphragm of 45mm/50mm gas water heater. A pleasant helper for upkeep of water heaters, fuel valves, Mainly used to extend water pressure. When the water film ruptures, it is going to leak. When the water number is large, the water pressure at the water movie will decrease, and there's almost no water leakage. When the amount of water is small, the water strain on the water movie will increase, however the leakage price would be faster. ThePackage Includes: 10 items of 45mm/50mm size. Specifications: Material: Plastic Weight: 25g/35g Size: 45mm/50mm Color: Black Package Includes: 1x Pressure Diaphragm Note: 1 allow 1-2cm mistakes due to instruction manual measurement, just remember to don't mind before you order. 2 to the difference between different monitors, the picture will not replicate the particular shade of the item.