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

These bulbs are sized to fit tight spaces such as signs, control panels, indicators, and flashlights.

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

Fit these bulbs in tight spaces such as signs, control panels, indicators, and flashlights.

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

Pins on either side of the base lock these bulbs into sockets.