A filter (300) to be placed in a flow of blood through a vessel, comprising: a hub (310) disposed along a longitudinal axis； a plurality of anchor members (330) extending from the hub, each anchor member including either a cranial extension (340) or a caudal extension (350) at a distal end thereof, at least one anchor member distal end spaced from the hub at each of a first, second, and third distance along the longitudinal axis； and a plurality of locator members (320), each locator member extending from the hub between an adjacent pair of anchor members； wherein the cranial extensions include a cranial hook (342) and a cranial limiter (344) extending separately from a cranial base having a width greater than a width of the anchor member.
