An occlusion device for a vascular or biological lumen includes a plurality of coiling members held together at both the proximal and distal ends by retaining features. A restraining loop can hold coiling members together at a point along a length of the coiling members. The coiling members are delivered simultaneously to form a coil pack to occlude a target location in the lumen. One or more of the coiling members has at least a portion with a larger curl diameter than other coiling members to secure the occlusion device against lumen walls at the target location. The coil members may have different or varying material moduli. The device may be used, for example, for occluding a vessel to block blood flow to an artery supplying blood liver (hepatic artery), kidney (renal artery), spleen (splenic artery) or intestines (mesenteric artery).
