An embolic device deployment system having a lumen with proximal and distal ends. An embolic device having a proximal retaining ring and an expandable member having a contracted and expanded state, with two apertures. The expandable member is disposed in the lumen in the expanded state. An engagement member has a distal loop extending through the retaining ring and a proximal loop extending into the lumen. The detachment member slides within the lumen and another of the apertures and is disposed through the loops. It comprises a bump on the detachment member between the loops. When the detachment member is in the distal loop and the distal loop is disposed within the retaining ring, the embolic device is in an engaged position. Pulling the detachment member withdraws it from the distal loop. The bump contacts the proximal loop to assist in the disengagement of the distal loop from the retaining ring to release the embolic device.
