A gearbox comprising: a reference member, a front carrier, a rear carrier, and one or more offset members; the reference member comprises a central axis, a front carrier axis, and a rear carrier axis; the front carrier comprises one front central axis and a number of front offset axes equal to the number of offset members; the rear carrier comprises one rear central axis and a number of rear offset axes equal to the number of offset members; each offset member comprises a front member axis and a rear member axis; and wherein: all axes (1, 2, 3, 4, 5, 6, 7, 8, 9) are parallel; the front carrier axis and rear carrier axis are spaced apart by a carrier distance; each front offset axis and the front central axis are spaced apart by an offset distance; each rear offset axis and the rear central axis are spaced apart by the offset distance; all front offset axes are arranged circumferentially around the front central axis; all rear offset axes are arranged circumferentially around the rear central axis; each associated front member axis and rear member axis is spaced apart by the carrier distance; the front central axis is co-axial and rotatably coupled to the front carrier axis; the rear central axis is co-axial and rotatably coupled to the rear carrier axis; each front member axis is co-axial and rotatably coupled to a different front offset axis; and each rear member axis is co-axial and rotatably coupled to a different rear offset axis. a reference member, a front carrier, a rear carrier, and one or more offset members; the reference member comprises a central axis, a front carrier axis, and a rear carrier axis; the front carrier comprises one front central axis and a number of front offset axes equal to the number of offset members; the rear carrier comprises one rear central axis and a number of rear offset axes equal to the number of offset members; each offset member comprises a front member axis and a rear member axis; and wherein: all axes (1, 2, 3, 4, 5, 6, 7, 8, 9) are parallel; the front carrier axis and rear carrier axis are spaced apart by a carrier distance; each front offset axis and the front central axis are spaced apart by an offset distance; each rear offset axis and the rear central axis are spaced apart by the offset distance; all front offset axes are arranged circumferentially around the front central axis; all rear offset axes are arranged circumferentially around the rear central axis; each associated front member axis and rear member axis is spaced apart by the carrier distance; the front central axis is co-axial and rotatably coupled to the front carrier axis; the rear central axis is co-axial and rotatably coupled to the rear carrier axis; each front member axis is co-axial and rotatably coupled to a different front offset axis; and each rear member axis is co-axial and rotatably coupled to a different rear offset axis. all axes (1, 2, 3, 4, 5, 6, 7, 8, 9) are parallel; the front carrier axis and rear carrier axis are spaced apart by a carrier distance; each front offset axis and the front central axis are spaced apart by an offset distance; each rear offset axis and the rear central axis are spaced apart by the offset distance; all front offset axes are arranged circumferentially around the front central axis; all rear offset axes are arranged circumferentially around the rear central axis; each associated front member axis and rear member axis is spaced apart by the carrier distance; the front central axis is co-axial and rotatably coupled to the front carrier axis; the rear central axis is co-axial and rotatably coupled to the rear carrier axis; each front member axis is co-axial and rotatably coupled to a different front offset axis; and each rear member axis is co-axial and rotatably coupled to a different rear offset axis.