Also known as FC. Unit of illuminance – light falling on a surface or object. One lumen falling on one square foot equals one-foot candle.

Used with two three-way switches to allow a fixture to be controlled from three or more locations.

A plano-convex lens that has been flattened into a disk or sheet to focus light into a beam.

Spacer strips of wood or metal attached to wall studs or ceiling members to which surface material, such as wallboard, is fastened.

Replaceable safety device that provides circuit overload protection.

Mounting wall box dimmers or other devices together in the same enclosure and faceplate.

An adjustable ring that holds the PAR or MR lamp by its rim. A gimbal ring track fixture has no housing.

Directional light at an acute angle, which emphasizes texture. The sources of grazing light must be close to the surface.

A flexible metal conduit that protects conductors.

Connecting electrical components to earth for safety.