Seller: number-one (384) 100%, Location: Los Angeles, California, Ships to: US, Item: 172350307387 This is a brass/steel twist type doorbell. The bell is an original 100+ year old doorbell. There are no markings on the bell. The bell is made of bronze and the back plate is made of iron. The twist key is made of brass. The connecting rod can be trimmed to fit a door up to 2 1/2 inches thick. The bell could also be mounted through the wall using a longer connecting rod. The bell works by turning the key in either direction. The bell base is 4 1/4 inches in diameter and the bell is 3 1/4 inches in diameter. The twist key plate is 2 1/2 inches in diameter. The bell and back plate have a bronze finish with raised areas in copper, all in excellent condition. The twist key is polished brass. These are very practical doorbells for any house. They are very reliable, maintenance free and easy to install. If you want an authentic piece of history for your front door you may want to consider this bell.