This is directed to a hook and receiving element combination for securing components forming the shell of an electronic device. The receiving element can include a beam connected to the outer shell component and operative to deflect as the hook element approaches the receiving element. To limit deflections of the outer shell component, the beam can be restrained at opposing ends in directions perpendicular to the beam length, but free to slide along the beam axis. In some embodiments, the receiving element can include a lip for guiding the deflection of the beam as the beam contacts the hook element. In particular, the lip can ensure that the beam deflects at an angle relative to the hook element motion such that a smaller hook element motion is required to engage the beam.