If you have the small halogen lights in your bathroom, then:Turn off the lights and make sure they are cool. DO NOT touch the bulb with your fingers because the oil on your fingers will cause the bulb to fail. Use a cloth or cotton gloves. The bulb push in and pull out – they do not twist. The bulbs are halogen 40 watts/clear 120 volts. Sylvania 40CAPSYLITE/G9/CL. Keep the package so you know what to buy the next time!