The Type IJS relay is an induction disk synchronism check relay that has two shaded pole U-magnet driving elements acting on opposite sides of a single rotating disk. One operating element drives the disk in the contact closing direction and the other in the restraining or opposite direction. The disk shaft is restrained by a spiral spring, to hold the contacts open when the relay is de-energized. The motion of the disk is slowed by permanent magnets to give a time delay.