An orthographic illustration of a die displaying sides 1, 4, and 5.

An orthographic illustration of a die displaying sides 2, 4, and 1.

An orthographic illustration of a die displaying sides 2, 6, and 4.

An orthographic illustration of a die displaying sides 4, 1, and 2.

An orthographic illustration of a die displaying sides 4, 2, and 6.

An orthographic illustration of a die displaying sides 4, 5, and 1.

An orthographic illustration of a die displaying sides 4, 6, and 5.

An orthographic illustration of a die displaying sides 5, 1, and 4.

An orthographic illustration of a die displaying sides 5, 4, and 6.

An orthographic illustration of a die displaying sides 6, 4, and 2.

An orthographic illustration of a die displaying sides 6, 5, and 4.

Signal for the letter D, or the number four.