Solar panels are internal providing less chance for damage and theft. Features completely redesigned rugged and durable co-polymer case with breakaway internal candle. Servicing is made easy with a snap-lock case and vertically positioned batteries. The "D" cell batteries simply drop into the light base and the case is ready to be snap-lock closed. The case will remain closed and secure during the rough transportation and service work. The impact absorbing breakaway candle reduces internal damage. Bright and dependable LED's coupled with power efficient, reliable moisture proof circuitry, provide trouble-free operation. Type A, C and 3 Way, 3 volt lights comply with current ITE purchase specification referenced in the Federal MUTCD. In flash mode batteries should last 20 months. Sensor in light causes them to turn on at night only. Batteries not included. Empco 2006+ Model.