Upgrade your old white C9 bulbs with HolidayLEDs.com C9 LED retrofit replacement bulbs. Each C9 bulb uses 5 high power LEDs. Rated for 50,000 hours of use, you will not have to worry about climbing up on an icy ladder to change your lights with our C9 replacements. Five super bright LEDs per bulb. Package of 25 bulbs. Dimmable.