[SD/Misc] Empty Equipment Icons

I've browsed around the spells section and found a few systems using icons that represent empty equipment slots (Helmet,Gauntlets,Armor,Amulet, etc.) Thing is, I don't know where they got these icons as there are no credits for them.

Does anyone know where to get these said icons? I've used different keywords in the resources section but can't seem to find these empty placeholder icons for an inventory.