Medium-bases screw-in fluorescent. Light output equivalent to 60 watt incandescent bulb. 4.75 inch overall height. 10,000 hour life. •Instant-on, no lamp flicker •Same light output as a 60 watt incandescent bulb. •Very short (4.75 inches) to fit most applications. •10,000 rated life. •900 lumens light output