Bulbs have two filaments, which operate at different brightness levels.

These miniature bulbs are sized to fit older telephone switchboards, signs, instruments, and indicators.

These bulbs are sized to fit tight spaces such as indicators and vehicle lights.

These bulbs are small, but very bright, so they're often used in flashlights and optical instruments such as projectors and microscopes.

Offset pins on the base lock these bulbs into sockets. One pin is slightly higher on the base than the other pin.

Commonly used in signs, instruments, indicators, and flashlights.

Concentrate and direct light between the bulb on your circuit board and a display.

Also known as beacon lights and signal lamps, these bulbs provide high-intensity light so they're often used in security warning devices and machinery.

Pins on the base lock these bulbs into sockets to withstand vibration. They're often used in machines and elevators.