Devices, delivery systems and delivery techniques for an occlusion device for the closure of physical anomalies, such as an atrial septal defect, a patent foramen ovale (PFO), and other septal and vascular defects are described. The devices, delivery systems and delivery techniques relate particularly to, but are not limited to, a patent foramen ovale (PFO) occluder made from a polymer tube, specifically, a petal-shaped occluder. In certain embodiments, the catch system includes a catch member with a screw catch mechanism for connecting to the occluder. A delivery system for use with the catch member includes a component for rotating the catch member relative to the occluder to engage the screw catch mechanism.