Caddellite Helm

The Caddellite Helm is a special piece of equipment which appears in Ultima VII.

Description
Learning that the defenses of the Cube Generator were unsurpassed without some manner of protection from the high-pitched shrieking noise emitted, the Avatar was forced to seek out the rare sound-dampening metal known as Caddellite, which existed only on the forgotten islands of lost Ambrosia. After the hero retrieved this rare meteoric metal, they were able to commission Zorn of Minoc to fashion it into enough helms to outfit their party, and was thereby able to launch their assault on the blackrock cube.

A Caddelite helm offers comparable protection to a Great Helm.

Trivia

 * In the SNES Port of Ultima VII, the caddellite helm was an artifact which Zorn had made for a member of the Fellowship, and it had been hidden in the Dungeon Covetous.
 * Caddellite is a reference to Michelle Caddel, also known as Mariah, who was Richard Garriott's personal secretary at  Origin.