Probably the cheapest PCB ruler on the market, and an extra nice one as well: Our small ruler shows a lot more helpful information than only SMD footprints:

- Via and wire gauges 0.3 to 4 mm (AWG 29 to 7)
- Font sizes
- SMD footprints
- Pin pitch (1.27 - 2.0 - 2.54 mm)
- Radius 1, 2 and 3 mm
- Protractor 180 degrees
- Voltage divider calculation
- Inch - Mil - mm conversion
- Resistor colour codes
- PCB trace thickness and max. current