These bulbs are small, but very bright, so they're often used in flashlights and optical instruments such as projectors and microscopes. Brightness is measured in lumens; the higher the lumens, the brighter the bulb.

Halogen bulbs are slightly more energy efficient than incandescent bulbs, but they generate more heat.

These bulbs are sized to fit tight spaces such as signs, control panels, indicators, and flashlights. Brightness is measured in lumens; the higher the lumens, the brighter the bulb.

LED bulbs last longer and are more efficient than other technologies. They generate little heat and withstand vibration.

Offset pins on the base lock these bulbs into sockets. These bulbs are sized to fit tight spaces such as indicators and vehicle lights. Brightness is measured in lumens; the higher the lumens, the brighter the bulb.

Bulbs have two filaments, which operate at two brightness levels. The first filament illuminates a light and the second emits a brighter light similar to a tail light and brake light.

Brightness is measured in lumens; the higher the lumens, the brighter the bulb. Color rendering index (CRI) is a measurement on a scale of 0-100 of how accurately the light from a bulb represents an object's true colors; the higher the number, the more natural the colors appear. Any CRI value over 80 will show colors true to life. Bulbs with a warm light appearance have yellow tones. Bulbs with a neutral light appearance are often used in workspaces. Bulbs with a cool light appearance have white/blue tones and are good for inspecting. A bulb’s estimated yearly cost is based on 3 hours of usage per day at $0.11 per kWh. They contain small amounts of mercury (for disposal information, visit www.epa.gov/cfl).