More about 1 7/8"W x 1 7/8"H Michael Healy Golf Ball Doorbell Ringer, Chrome... Michael Healy is an accomplished Rhode Island artisan with years of metalworking experience and an eye for creativity. Each unique door knocker is crafted individually and signed by the artist Michael Healy. All Michael's Door knockers are cast in Solid Brass, Bronze, Nickel Silver or in a combination of these metals. Brass is an alloy containing 70% copper, while bronze contains 85%. The additional copper content gives bronze a reddish undertone. Nickel is added to the bronze alloy to create the warm silver color of our Nickel Silver alloy. Add warmth and character to your home with a Michael Healy door knocker.