Ellipse shape (ovoid olivary oval shaped), more comfortable. This is a restraint system that is both high-function and high-fashion. Made from strong, cold, heavy steel allowing long use and wear. Our blacksmith custom makes this item by hand. The inside diameter is 7.7 cm x 6.5 cm, thickness 0.5CM, high is 2.2 cm.(2) The weight of this item is approximately 520g.