has a radius generally equal to one half the length of the headpiece 30 in the preferred embodiment the radius of the distal section 36 of the headpiece 30 is approximately 0 008 inches the proximal section 38 of the headpiece 30 is cylindrical in shape and has a radius generally equal to the radius of the distal section 36 of the headpiece 30 filaments 40 are molded into or bonded with the spherical members 32 the filaments 40 are made of nylon but may also be made of acrylic or a polymer preferably the length of the filaments 40 may range from about 0 003 inches to about 0 010 inches in the preferred embodiment the length of the filaments 40 is approximately 0 005 inches the filaments 40 may cover the surface of a spherical member 32 from 0 percent to 50 percent there is a coverage area of about 10 percent in the preferred embodiment 0031 fig3 illustrates the deployment catheter 18 with the aneurysm embolization device 10 during transportation through a delivery catheter 42 positioned in a vessel 44 the headpiece 30 is tightly held within the lumen 24 of the deployment catheter 18 in this position the headpiece 30 serves to provide a fluid tight seal at the distal section 26 of the deployment catheter 18 preferably the proximal section 16 of the deployment catheter 18 is formed of pebax material having a durometer in a range of about 62 d to 75 d the proximal section 16 is sufficiently flexible to transverse the vasculature of the.