Here you see a traditional SIM with measurements 15 * 25 mm. As only the metal contacts are the working part you can downsize it to the smaller Micro SIM size.
The same traditional 2G SIM ist shown here again but you can see the measures needed for the Micro SIM cut which are 12 * 15 mm.
There are invisible contacts on the SIM Card as well. This means that cutting the SIM might cause problems with the functionality of the SIM. It is recommended to use a die cutter to downsize the SIM.
Take one of our Micro SIM adapters and just put the Micro SIM in and you can use it again for models which still need the traditional size.
Another customer of ours (from Brazil!) was very kind and filmed the adapter in use on an iPhone, simple huh?