Elastic engaging element

An elastic engaging element for engaging a second component to a first component stacked on top of the second component, the first and second components each having corresponding through holes, the engaging element comprising:

• an elastic coil having a first end and a second end, the second end having an exterior diameter at least larger than a second diameter of the through hole of the second component, in order to have the second end keep propping against a bottom surface of the second component;
• an extension wire integrated with the elastic coil and extending from the first end of the elastic coil, passing through the whole elastic coil, and to the second end of the elastic coil;
• and
• a hooking portion integrated with the extension wire and located in a region outside of the elastic coil, the hooking portion having a contour size at least larger than a first diameter of the through hole of the first component and being capable of elastically deformed and passing through the through holes of the first and second components and then hooking up to a top surface of the first component.