It was an ancient percussion instrument, from wood, metal, clay or their combination, with varied, penetrating and vague sound that accompanied the rhythm in the religious processions.
It usually consisted of a handle and U-shaped frame that had either moving parallel rods (striking in its walls), or constant rods with moving perforated noise-making objects.
The executor held it in vertical position and shook it or rocked it rhythmically.
SOURCES: M.L. West, Ancient Greek music, Solon Michailidis, Encyclopaedia of Ancient Greek Music, Pollux, Onomasticon.