A Note on Magical Arms and Armor

So a side note on magical arms and armor.  On Martapa, and on many fantasy worlds, there are lots of magical arms and armor.  Different kinds and shapes, materials and magic, but one ability stays constant.  On Martapa the weapon, shield or armor shapes to the wielder or wearer.  An example of this is the magical elven chainmail Richard Goldenstein uses and is mentioned in the High King's Sword.  Richard was a large man, but later on Sebastion Blackthorn, though not that small, gains the mail and is smaller then Richard.  Yet, the mail fits him perfectly.  Richard's shield, which Elly acquires, also shrinks to fit her small stature, but is no less magical.  There are limits to the magic of size change, such as a dragon size item will not shrink to a fairy sized item or visa versa.  This size changing does not damage the magic of the item and is hardly noticed by the new owner of the weapon or armor.