This is a semi-circular neodymium magnet made of rare earth neodymium material. It has a standard semi-circular diameter, equivalent to cutting a circular magnet into two halves. It has a diameter of 25.4 mm and a thickness of 3 mm. Its special feature is its magnetization direction...
1 inch diameter rare earth neodymium magnet is a powerful rare earth magnet made from an alloy of neodymium,here is a more comprehensive introduction to 1 inch rare earth neodymium magnets....