SFSpecFits

Identification guides

Use these pages when you need to decode a label, measure a component, or understand what a standard designation actually means. Each guide explains the naming logic so you can identify the right part even when the original is missing or illegible.

Battery identification

Bulb base identification

Related cheat sheets

Looking for a device guide instead?

If you already know the device and want the answer fast, see the Device Guides — they cover batteries, bulbs, fuses, fasteners, and cables by device type.