Gauntlets similar to these are made historically for protection of the hands. While we could use them for that today, most likely someone would want this for costume purposes or just because it's cool!
They work well while being worn, allowing full function of the hands (given limitation of mittens, of course), and I use a pair myself for my martial arts practice.
These can be made from mild steel or stainless steel, depending on your preferred look and how strong you want them to be. Stainless is tougher! Add $50 for stainless steel.