Abstract: A vaso-occlusive device, delivery system and method of delivery to a selected site of the vessel in a manner allowing the vaso-occlusive device to substantially assumes a diameter of an inner surface of the vessel or aneurism sac at the site of the embolization procedure. The vaso-occlusive device or embolic coil has specific properties of wanting to float and conform to the diameter of the aneurysm sac thereby enabling retractability and rapid disconnect detachment for such embolic coil, and a predetermined shape requiring fewer embolic coils per embolization procedure advantageously improving patient risk, and the cost and time of the procedure. A method for deploying the embolic coil with such specific properties to the site of an aneurysm using a delivery system configured for deploying the embolic coil features inserting, and/or reconnecting for positioning and reinserting the embolic coil.