NEC UC2-5NU

The current rating of a contact is defined as the current level that creates a certain temperature rise of the contact spring — usually 20°C or 30°C. Both electrical and thermal factors govern the heat created by the current.

There are 2 different types of 'coil'; one has copper on it (IUD) and the other contains hormone (Mirena IUS). Both are over 99% effective at protecting against pregnancy.