The button top 706 is part of the button assembly, and is configured to receive the user press on the button assembly. The front cover plate 708 therefore includes a button opening 710 configured to expose the button top 706 of the button assembly on the front cover plate 708. The button top 706 has a first diameter that is substantially smaller than a second diameter of the opening 710 of the front cover plate 708. The button top 706 can move vertically in a direction perpendicular to a plane of the button opening 710 e. g. , in a downward direction into or out of the device housing 702 when a user presses on the button top 706.