Improve your outdated holiday display buy replacing your inefficient C9 incandescent bulbs with LEDs. Our red C9 LED retrofit bulbs use 99% less energy than incandescent bulbs and are super bright. Each C9 bulb contains five high power LEDs so these bulbs will shine brightly unlike other C9 LED replacements. In addition to the energy savings, these bulbs will last 10 times as long as incandescent C9 Christmas lights and are constructed of a durable epoxy plastic not fragile glass. Stay inside where it's nice and warm this holiday season and off your icy ladder replace old C9 incandescent bulbs with HolidayLEDs.com red C9 Christmas light bulbs. Box Of 25 Bulbs. Dimmable.