The most common plug in the world, power plug type C, and electrical outlets (CEE 7/17) are used globally except in the United Kingdom, Ireland, Malta, and Cyprus.
The type C plug has two round pins, which are ungrounded and unpolarized.
The plug’s 4 mm round pins have a length of 19 mm. At the base, the pins are 18.6 mm apart and 17.5 mm apart at the tip. On the pins are 10 mm insulated sleeves.
The type C plug is flexible and can fit into any outlet as long as it gives room for 4.0–4.8 mm round contacts on 17.5–19 mm centers.
The most common of this plug is used for appliances that require 2.5A.
There is another rare variant that has a current of 10 A or 16 A. They bear similarity to the 2.5 A version but have no insulation and have a diameter of 4.8 mm.
High energy appliances, most of which do not need earthing, such as vacuum cleaners and hair dryers, comes with this type C plugs version.
The type C plug has a lot of popularity and is used in almost every country, especially in developing countries.
While type C has immense popularity, the type C electrical outlet or socket is not as popular as its plugs counterpart. The type C socket is ungrounded and old and is a variant of E, F, H, J, K, L, N, and O sockets.
The fact that type C sockets are ungrounded and unearthed is why the socket isn’t in use.
Most countries prefer grounded sockets and earthed sockets, which has led to unearthed sockets to be outlawed.