This Altar Bell is made of Brass and is Nickel Plated (electroplated). The Bell stands 6 inches (15 cm) tall and 6 inches (15 cm) wide and has a base dia of 2.4 inches (6 cm).
Altar Bells: or sanctus bells are typically a small hand-held bell or set of bells. Sanctus bells derive their name from being rung first during the Sanctus [Holy, Holy, Holy Lord...]. They have been rung as part of the celebration of the Holy Sacrifice of the Mass in the Church for more than 800 years. The primary reason for the use of sanctus/altar bell(s) is to create a joyful noise to the Lord as a way to give thanks for the miracle taking place atop the Altar of Sacrifice. An ancillary function of the bell(s) is to focus the attention of those attending the Mass that a supernatural event is taking place on the altar. These bells are also commonly referred to as the Mass bell, Altar Bell or Sanctus bell (or bells, when they are more than one). (source: www.newadvent.org)