Affect of PK items on digital devices

[formula]

I've been thinking about picking up a PK ring for a while now but I'm worried about the affect it will have on mobile phones, credit cards and over devices such as tablets.

Anyone who wears or uses a PK ring often, can you share some of your experience on whether it's safe to have around digital devices (or even some optical devices, like watches)?

 

[WitchDocIsIn]

Never had a problem when I wore one. I certainly wouldn't sit there with the ring resting on devices, but casual contact shouldn't be an issue, and I used the strongest you could get.