C-series metal domes are the circle shape tactile dome switches, which with the softer click feeling than the F-series. This item is very suitable for the double layers printed circuit boards. They are designed to be pushed past the flat plane by .005-.010" for optimal tactile feedback, this over-travel allows it to reach a contact area below the plane. There are some one with the dimples in the center, As the function of the dimples can increase the contact area and enhance the stability of metal dome. So it’s to choose to most customers is the metal dome with dimple. If you want to learn more about the C series metal domes, please contact us anytime, we are glad to be at your service.