Medieval Armet Helmet Base

Visor: https://www.roblox.com/catalog/12401630188/

Raised variant: https://www.roblox.com/catalog/12401637939/

Plumes: https://www.roblox.com/catalog?Keyword=plume&Category=1&CreatorName=Iskender%27s%20Excellent%20Emporium&CreatorType=Group&salesTypeFilter=1

Shirt: https://www.roblox.com/catalog/13084364448/

Pants: https://www.roblox.com/catalog/13083369713/

More items here: https://www.roblox.com/catalog?Category=1&CreatorName=Iskender%27s%20Excellent%20Emporium&CreatorType=Group

This is technically a later "close helmet," but the distinction between armets and close helmets is a modern one, not a period one. Although armets and close helmets are closely associated with medieval knights, they only started appearing around the late 1400s, making them more of an early modern helmet.