This d120 has one hundred twenty triangular faces numbered 1-120. The shape is a polyhedron known as the disdyakis triacontahedron. This shape is the ultimate fair die allowed by mathematical symmetry. The die is 2.0" (50 mm) in diameter and weighs 1/5 of a pound (0.1 kg). This d48 has forty-eight triangular faces numbered 1-48. The polyhedron is known as the disdyakis dodecahedron. The die is 1.3" (33 mm) in diameter. On both dice, the numbers are distributed perfectly uniformly, so that the sums of the number groups of each type are uniform. E.g., the twelve groups of ten numbers on the d120 all sum to 605.