A vaso-occlusive device delivery system includes a delivery wire assembly having a core wire disposed in a delivery wire lumen, and a vaso-occlusive device having a tapered proximal end and defining a vaso-occlusive device lumen, wherein a tether is disposed in the lumen and secured to the core wire. A link may be attached to each of the core wire, the proximal end of the vaso-occlusive device, and the tether. Alternatively, the system may include a transition member attached to the vaso-occlusive device and secured to the core wire.
