Reliable sealing and anti-aging. Good helper heater, fuel valve and other maintenance. Made of pleasant materials, it can be used for a protracted time. Replacing the outdated one is a reputable choice. Type: Gas water heater kit Colour: black Material: rubber Size: 54mm diameter Package Contents: 100 x strain diaphragm Only the above equipment content, other merchandise should not included. Note: Light and diversified displays may cause the color of the item within the photo a bit of diverse from the real thing. The length allowed error is +/- 1-3cm.