Crystal Mask of Knowledge

This mask features a piece of curved golden crystal that covers the forehead. The crystal is attached to the front of a dark brown cloth cap.

A crystal mask of knowledge grants you a +5 competence bonus on a specific type of Knowledge check. For instance, one mask would add the bonus on Knowledge (psionics) checks, while another would do so for Knowledge (history).

Prerequisites: Craft Wondrous Item, Knowledge 5 ranks of the appropriate type.

Cost to Create: 1,250 gp, 100 XP, 3 days.

Source: Magic Item Compendium, page 91.