This filament is 30mm long and glows a bright green color. It is the same filament as used in "Edison Like" light bulbs. Made from a string of micro LEDs connected in parallel and then mounted in stiff silicon (do not try to flex these as they are fragile and will break). Operates on 3VDC @ 100mA. These look absolutely amazing when they are glowing. Note: Metal tap with a micro hole in it is (+). Brand New!