High-intensity discharge (HID) and LED HID-replacement light bulbs and lamps generate a lot of light and can be left on for long periods of time. They are used in streetlights, gymnasium lights, stadium lights, warehouse lights, parking garage lights, and similar applications for lighting large, open areas. These bulbs require a fixture with a ballast that regulates the voltage supplied to the bulb. Standard HID bulbs spread light in all directions and are typically used in fixtures with a reflector that helps direct the light to where it's needed. LED HID-replacement bulbs are more energy efficient and need to be replaced less often than standard HID bulbs. They emit light in a specific direction. HID bulbs must be installed in the operating position that is recommended by the manufacturer in order to maximize the bulbs' performance and life. Installing the bulbs in an incorrect operating position can cause some bulbs to rupture.