Why is this power cable sometimes polarized and sometimes not?

Micro-USB power supply Initially, a computer with Internet connection and the ability to flash your microSD card is also required Next Step

EU Schuko CEE716 plug to 2 Slot Polarized Figure 8 AC Adapter Power Cord · 90 Degree Angled EU Schuko CEE716 plug TO IEC 320 C7 2-Slot

200 slot What is this?This is a two-prong power cord Its connectors conform to 2-Slot to C13 types and are mainly used to replace worn or missing power cords

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