Well you see, despite popular belief, the hammer of sol is not actually as elegant as one might imagine, mainly because the handle occupies far less space than the hammerhead itself. This leads to an inverse in pull upon the hammer's head, which can cause it to be ineffective at hitting nails, and generally any form of wood working. In order to balance this, I believe they need to put a counter weight on the handle, so that it may be used as a proper hammer would be.