An embolisation device for promoting clot formation in a lumen comprising at least two segments, each segment comprising a stem and a plurality of flexible bristles extending outwardly from the stem, the bristles having a contracted delivery configuration and a deployed configuration in which the bristles extend generally radially outwardly from the stem to anchor the device in a lumen, comprising a proximal bristle segment and at least one distal bristle segment, and either an intermediate marker between the most proximal segment and the segment which is adjacent to the most proximal segment, a proximal marker proximal the most proximal segment or a distal marker distal of the most distal segment.
