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 two angled members (25L, 25U); at least two cone members (18L, 18U) for engagement with the at least one slip, each cone member (18L, 18U) comprising at least one angled member (27L, 27U) for engagement with a respective angled member (25L, 25U) of the slip; and at least two cone member expansion devices (17, 20), each cone member expansion device of the at least two cone member expansion devices (17, 20) being for engagement with at least one of the two cone members, each cone member expansion device (17, 20) comprising at least one angled member (33L, 33U) for engagement with a respective at least one further angled member (31L, 31U) of each cone member, wherein the two cone member expansion devices (17, 20) are spaced apart along the longitudinal axis of the mandrel, wherein one cone member expansion device is fixed to the mandrel and the other cone member expansion device is moveable along the longitudinal axis of the mandrel with respect to the said one cone member expansion device such that the moveable cone member expansion device can be selectively moved toward and away from the said one fixed cone member expansion device, wherein the two cone members (18L, 18U) are spaced apart along the longitudinal axis of the mandrel, wherein each end of the slip is mounted in one of the cone members (18L, 18U), and wherein one cone member is engaged with the fixed cone member expansion device and the other cone member is engaged with the moveable cone member expansion device such that the said one cone member can be selectively moved toward and away from the said other cone member when the moveable cone member expansion device is selectively moved toward and away from the said one fixed cone member expansion device to respectively move the slip radially outwardly and inwardly with respect to the mandrel. 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 two angled members (25L, 25U); at least two cone members (18L, 18U) for engagement with the at least one slip, each cone member (18L, 18U) comprising at least one angled member (27L, 27U) for engagement with a respective angled member (25L, 25U) of the slip; and at least two cone member expansion devices (17, 20), each cone member expansion device of the at least two cone member expansion devices (17, 20) being for engagement with at least one of the two cone members, each cone member expansion device (17, 20) comprising at least one angled member (33L, 33U) for engagement with a respective at least one further angled member (31L, 31U) of each cone member, wherein the two cone member expansion devices (17, 20) are spaced apart along the longitudinal axis of the mandrel, wherein one cone member expansion device is fixed to the mandrel and the other cone member expansion device is moveable along the longitudinal axis of the mandrel with respect to the said one cone member expansion device such that the moveable cone member expansion device can be selectively moved toward and away from the said one fixed cone member expansion device, wherein the two cone members (18L, 18U) are spaced apart along the longitudinal axis of the mandrel, wherein each end of the slip is mounted in one of the cone members (18L, 18U), and wherein one cone member is engaged with the fixed cone member expansion device and the other cone member is engaged with the moveable cone member expansion device such that the said one cone member can be selectively moved toward and away from the said other cone member when the moveable cone member expansion device is selectively moved toward and away from the said one fixed cone member expansion device to respectively move the slip radially outwardly and inwardly with respect to the mandrel.