Door Bells, well made and distinctive. Choose your Door Bells here today. This chrome mechanical doorbell is a lovely solution for homes without a hardwired doorbell. It mounts through the door and the turnkey turns a real bell-no electronic chimes here! The maximum door thickness is 2". The bell diameter is 4". The total projection is 2 1/2" and from tip to tip behind the bell is 5 1/2".