UltraLED's serviceable LED "lights" come in both single (1156) and double (1157) contact bulbs in addition to 194 clearance light bulbs. The bulbs utilize a combination of traditional bulb/ socket base and SMD technology, creating a single source SSL. The first of their kind within fleet based operations, according to the manufacturer, they offer an easy solution to upgrading the incandescent lights in a fleet to LED lights with the simple change of a bulb during routine maintenance. LEDs require less frequent replacement, according to the manufacturer.