Abstract: A bracelet type fastening device for releasably affixing the ends of a bracelet type item to each other to secure the item on a part of the body of a wearer comprises a first fastening member pivotally affixed to a first end of a bracelet type item and having a semicircular support part of predetermined diameter and a catch pin affixed to the support part and extending diametrically thereacross. A second fastening member is pivotally affixed to a second end of the bracelet type item and has a spherical hook member having a diameter smaller than the predetermined diameter and a slot formed radially therein for accommodating the pin of the first fastening member. The slot extends in a plane inclined at a predetermined angle with a central plane of the second fastening member and opens toward the item.