Knight-Errant's Mail is a heavy armor set. The 5-piece set bonus adds 200 Weapon Damage to your One Hand and Shield abilities. When you use a One Hand and Shield ability, you heal for 1250 Health.
The Knight-Errant's Mail set is part of the base game. It drops in Blackheart Haven in Bangkorai. Each set item is bound on pickup. You can acquire heavy armor, weapons and jewelry of this set in the Mercenary motif style.