His trumpet is a large conch, or sea-shell.

The three sea elves stood blowing on large conch shells, their sonorous notes reverberating through the area.

I stumbled to the dresser and felt for a large conch I'd collected on the Outer Banks.

One is the Pututo, "a large conch on which they perform mournful music, as the accompaniment of their funeral dances."

"You should know that if you destroy it," he shouted, pointing up to the large conch-shell Thinker on a plinth well above Ella's head.