Use these bulbs in small instruments, such as microscopes, projectors, and inspection lights. A raised rim on the base holds the bulb at a fixed depth to keep light properly focused. Also known as midget flange-base bulbs, they’re sized to fit tight spaces.

The trade number, printed on the bulb or in an instruction manual, makes it easy to find exact replacements.

Use these bulbs for backlighting in instrument panels, including dashboard speedometers and warning lights. Brightness is measured in lumens; the higher the lumens, the brighter the bulb.

Often used in automotive dashboards, instrument panels, appliances, and indicators. A flat, pinched base presses directly into the socket to hold these bulbs in place. Brightness is measured in lumens; the higher the lumens, the brighter the bulb.

Light up automotive interiors, license plates, and dome lamps. These bulbs have pointed metal end caps that snap into place within festoon sockets. To replace a festoon bulb without a trade number, match the overall length, base diameter, and voltage. Brightness is measured in lumens; the higher the lumens, the brighter the bulb.