The present invention provides drumsticks for training percussionists to use proper form, which may increase learning speed and enable faster and more efficient drum strokes. A high pressure line extends between the source of high pressure fuel and the fuel inlet. A groove is formed at the periphery of the base and is provided with locking blocks at an appropriate position. Magnetic moments of the first and third AP coupled free layers are parallel with respect to one another and, because of a strong antiparallel coupling, the second AP coupled free layer pins magnetic moments of the first and third AP coupled free layers antiparallel thereto. From the reference node, the reference voltage is input to the comparator as a feedback voltage.