This invention includes: a base having a contact part that is in contact with a use surface; a movable part magnetically and detachably held above the base; a three-dimensionally movable support unit configured to support the movable part that is held by the base, in such a manner as to allow the movable part to move three-dimensionally and flexibly; and an attachment part via which the movable part is detachably attachable to a hand or a foot in a direct or indirect manner.