Type B vs. Type J

Type B adds a round grounding pin to Type A's two flat blades -- NEMA 5-15, the most common outlet in North America. The ground pin is deliberately longer than the power blades, so it connects before and disconnects after them, a safety-sequencing feature shared with several other grounded plug types worldwide.

Type J is Switzerland's own standard -- three round pins in a small hexagonal-bodied plug, in 10A and 16A variants. Its design directly influenced Brazil's and South Africa's later Type N standards, though reversed polarity during adaptation broke compatibility with its own descendants.