This is a triskadecagonal bipyramid with one side rotated 1/26th of a circle relative to the other. The pyramids have been truncated, slightly, and each flat end has a 2mm hole that opens to the interior, which has been hollowed in order to save printing costs.
Each face has a single upper case Roman letter intruded into its surface. The areas of the letters have been measured and the weight removed from each face normalized by adjusting the depth of the intrusion such that an equivalent volume is removed from each face. This die, unlike other alphabet or letter dice on the market, has an equivalent chance of producing any letter of the English alphabet. There are no duplicate letters or "null" faces.