An expandable slips system for use on a mandrel having a longitudinal axis, the mandrel adapted to be run into a borehole, the expandable slips system comprising: at least one slip which in use is adapted to be moved outwardly from the longitudinal axis of the mandrel to grip against and thereby engage a downhole formation, the at least one slip comprising at least one angled member; at least one cone member for engagement with the at least one slip, the cone member comprising at least one angled member for engagement with the at least one angled member of the slip; and at least one cone member expansion device for engagement with the at least one cone member, the cone member expansion device comprising at least one angled member for engagement with another at least one angled member of the cone member.