This product USES three main spring, a pay a gradient of spring stiffness spring, a total of four pieces of order. 1-3 of specifications are not 70 * 7, after a pay a reed specifications are 70 * 12, main pay spring material for 60 si2mn. Plate spring loading a length of 1100, the front length is 520, front end lug installed aperture Φ 17, back-end lug installed aperture Φ 28