A power adapter is disclosed. The power adapter includes housing parts that carries electronic components. To secure the housing parts together, one housing part includes snaps and another housing part includes protrusions and rails. During assembly, the protrusions slide under the snap, causing the snap to deflect in one direction, while the rails slide over the snap, which keeps the snap partially flat but also causes the snap to deflect in another direction. The engagement (during assembly) of the rails and the protrusions to opposing surfaces of the snap cause bi-directional deflection/bending of the snap. When each protrusion is positioned into an opening of the snap, the snap returns to a flat, non-deflected state, and the housing parts are secured together by the snap, protrusions, and rails. The rails support the snaps by limiting or preventing additional deflection of the snap, which subsequently promotes the housing remaining together.