A fastening device is disclosed. The fastening device has a vertical protrusion for fastening. A horizontal portion and an indicator are used for seating. The horizontal portion extends from the vertical protrusion for providing a clue to indicate that the fastening device is seated correctly. In embodiments, the clue is a color or a texture. In embodiments, a bellow is used with elastomeric properties. When the right load and torque are applied, the bellow covers the horizontal portion such that the color and/or texture of a perspective directed at the horizontal portion appear to be changed.