This file contains additional information, probably added from the digital camera or scanner used to create or digitize it.
If the file has been modified from its original state, some details may not fully reflect the modified file.
The cobalt shield is an accessory that is found in Dungeon chests, you can enter dungeons once you have killed Skeletron. The Cobalt shield provides 2 defence, and makes you immune to pushbacks.
This is extremely useful for when mining in the underworld, and you do not get pushback into the lava. Furthermore, mining meteorite is useful with a cobalt shield as it prevents the meteor heads from pushing about about.
I hope this video helped, if it did please give it a thumbs up and subscribe for more terraria videos! Thanks for watching :)