Features:brand new and high-quality OOTDTY Material: Nitrile rubber, features: reliable sealing and aging resistance. Pressure diaphragm of 45mm/50mm gas water heater. A nice helper for upkeep of water heaters, gas valves, etc. Mainly used to increase water pressure. When the water movie ruptures, it is going to leak. When the water number is large, the water pressure at the water film will decrease, and there may be almost no water leakage. When the quantity of water is small, the water strain at the water film will increase, but the leakage rate could be faster. The package includes: 10 goods of 45mm/50mm size. Specification:Material: Plastic Weight: 25g/35g Size: 45mm/50mm Color: Black Package Includes:1x Pressure Diaphragm note:1 allow 1-2cm errors due to guide measurement, just remember to do not mind earlier than you order. 2 to the adaptation between assorted monitors, the picture won't reflect the actual shade of the item.