These have been tested to confirm Sterling silver. The tops are sterling but the fitted back is stainless steel. These operate by opening the back slipping onto a button and then snapping back into place. these have been handmade from Arizona region. I have left these in an unaltered state and so they are a little bit tarnished but will clean right up if you decide you would like to do that. Some people like to wear the tarnished look. It's more vintage!