Abstract: An electrical component is supported within a housing molded of a plastics material, and the housing has an external groove which is interrupted by a plurality of peripherally spaced slots extending axially through the forward end portion of the housing. The slots provide for partially collapsing the forward end portion of the housing in response to pressing the housing into an opening within a panel so that the panel snap-fits into the groove. A retaining member is also molded of a plastics material and is mounted on the forward end portion of the housing to cover the slots. The retaining member has a corresponding plurality of circumferentially spaced and integrally molded ribs which are pressed axially into the slots to lock the housing firmly to the panel. The slots and ribs may have interfitting teeth to produce a permanent lock, and the retaining member can be adapted to carry a lens or other part which snap-fits into an annular recess formed by the retaining member.