A percussion vessel idiophone made from a rectangular block of wood hollowed-out through a slit chiseled in its topside. The performer, using a hammer-shaped wooden beater, strikes a side of the block to create a dry, clear, penetrating sound. Used to accentuate dance movements and to signal transitions in dance accompaniments. Not an integral part of a gamelan; any keprak can be used with any gamelan when that set is used for dance accompaniment.