LC4500 Series photo control feature low cost locking-type mounting and thermal-type controls for street lighting and other applications requiring a twist and lock type plug connection. Thermal-type photo controls provide dusk-to-dawn lighting control and a delay action, which eliminates loads switching OFF due to car headlights and lightning. The thermal-type controls feature a cadmium sulfide photocell and polypropylene case to seal out moisture. The design utilizes a dual temperature compensating bimetal and composite resistor for reliable long life operation over ambient temperature extremes. Polypropylene housing with UV protection.