The Hearty Berzerker Chain Mail represent a Shirt but has Chainmail around it, there is also what appears to be a Belt. This item does help in Quests.
Hearty Berzerker Chain Mail are clothing items worn on your Body. Their rarity is Uncommon. You must be level 30 or higher to use them. They are Bound. Below is a list of attributes they give you.
Regarding the spelling error, I sent a ticket to Monkey Quest. Below lists the context between me and the Team.
Me : Hiya! I was doing some editing on Monkey Quest Wiki when I noticed a spelling error. The clothing item entitled Hearty Berzerker Chain Mail is spelt incorrectly. It should be Berserker instead of Berzerker.
Charlotte K. : This isn't a typo :) It's what our creative team decided to use, haha. Thank you for your help!