PURPOSE: To prevent the coming off of a connection tool and a suspended article by eliminating such a defect of their coming off against the purpose of using a snap which is a conventional art.

CONSTITUTION: A snap is constituted in such a manner that a slide pin 12 is rotated and fitted to a main body 1 so as to be unmovable where it makes contact with an upper limit 7. Therefore, the coming off of a connection tool and a suspended article is prevented an accident and a loss can be prevented by employing against the use purpose above means for the snap.