Pins on the base lock these bulbs into sockets to withstand vibration. They're often used in machines and elevators. A bulb’s estimated yearly energy cost is based on 3 hours of usage per day at $0.11 per kWh.

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 or daylight 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.

LED bulbs last longer and are more efficient than fluorescent bulbs. They generate little heat, withstand vibration, and are shatterproof. LED bulbs are socket ready. They plug directly into a fixture and work with most instant-start electronic ballasts, but not all. For a full list of compatible ballasts select a part number and view product detail.

Brightness is measured in lumens; the higher the lumens, the brighter the bulb.

2-way bulbs operate at two brightness levels, as in high- and low-beam headlights.