Jump rings opener ring for chaimaille v2

Improved version of the previous model of jump rings opener. 

I noticed a wider side profile helps to put less stress on the finger.

Internal ring diameter 23.5mm, recess for rings of 2mm maximum thickess.

Added a hole on the side to insert a small 5x1 mm magnet to help work with galvanised steel. 

I'm also adding a different print profile without the magnet hole.

I'm including the .f3d file so you can modify the various dimensions, ring size, sloth thickness, magnet size.

If you need to have the various dimensions modified but cannot edit the .f3d file, just ask and I will do it.