Some electric lanterns use miniature fluorescent lamps for higher efficacy than incandescent bulbs. Others use incandescent bulbs mounted in reflectors. Fluorescent light bulbs and tubes internally produce ultraviolet light. Electric currents cause Joule heating, which creates light in incandescent light bulbs. They contained relays or stepping switches controlling digits consisting of incandescent light bulbs. CNT are under investigation as an alternative to tungsten filaments in incandescent light bulbs. The new porte cochere sparkled with 1,000 small incandescent bulbs. The rear lamps use the more modern rectangular style bulbs (7440/7443). Dimmable white LED bulbs are available. Light fixtures usually comprised single, bare bulbs. All HID headlamps worldwide presently use the standardized AC-operated bulbs and ballasts. It is commonly smoked in glass pipes made from glassblown Pyrex tubes and light bulbs. It also sells razors, batteries, light bulbs, and toothpicks. Soda-lime glass is typically used for windows, bottles, light bulbs, and jars. It specialized in the manufacture of light bulbs.