Specifying Metallic Parameters in IE3D v.14

I realize that this topic has been touched upon at least twice already, however I am still confused:

https://www.edaboard.com/thread136292.html
https://www.edaboard.com/thread51562.html

I am using MGRID at the moment and I am trying to change the "Metallic Strip Parameters" i.e. the strip thickness and conductivity

However, when I select two or more polygons and go to EDIT > OBJECT PROPERTIES > GROUP CHANGE METAL TYPE, I arrive upon a No.1 Metallic type that appears to be uneditable. When I double click on the highlighted metal type no window pops up.

Apologies in advance if I am missing something very basic.

Need to first add other metal type in basic parameter setting.