What is the electrical plug icon next to Stealth-skill?

[Magnimost]

See subject? Can't find explanation anywhere, and no tooltip pops up.

[Trenloe]

It's a breastplate - means armor penalties apply (disadvantage to stealth for certain armor types).

[Magnimost]

Ahhhhh, a breastplate - thought electrical plug doesn't really fit the theme :)

Thanks!