Description A reliable doorbell button replacement, made of nickel-plated copper material, is very reliable and durable for a long time. This universal ringer button is widely used and this doorbell button is simple and easy to install and operate. Give it to a friend and they will love it._ Features -Color:As Shown -Material:Nickel-plated copper -Size:16mm -This door ringer replacement button is compatible with most door ringer, we this wired chime button is a very practical product -Lightweight, small and space-saving, this replaceable doorbell button will not take up a lot of your space, easy to store and use. -Our replaceable ringer button, doorbell button is very practical and sturdy, not easily deformed, giving you a good experience. Ensure its popularity and practicality. -This universal chime button can replace the doorbell button with a cover that already exists. It takes only a few minutes to install and gives you a lot of pleasant and wonderful experience. -You can give this wired chime button as a gift to your friends and family to make their experience more enjoyable. Two types of wiring methods: normally open and normally closed: can be selected according to the application scenario Circuit description: The welding leg corresponding to the NO letter is called the constant opening; The welding leg corresponding to the letter C is called the common end; The welding leg corresponding to the NC letter is called the normally closed end Packing list: 4 x Doorbell Buttons