A servo valve comprising: a valve housing; a cavity formed in the valve housing and defining a longitudinal axis; and a member disposed in the cavity and axially-moveable therein, wherein the member comprises first and second cylindrical sections (32, 34) having a first radius (R1, R2), a central cylindrical section located between the first and second cylindrical sections (32, 34) and having a second radius smaller than the first radius (R1, R2), and first and second frusto-conical sections (37, 39) connecting the first and second sections (32, 34) to the central section and forming respective first and second frusto-conical surfaces (38, 40), wherein the member defines an annular channel radially between the member and the valve housing, and the annular channel is bounded by the first and second cylindrical sections (32, 34), and wherein the valve housing comprises a plurality of ports (48A, 48B, 48C), each forming a fluid passage through the valve housing in fluid communication with the annular channel, the plurality of ports (48A, 48B, 48C) comprising first and second ports (48A, 48C) each defining a diameter, characterised in that: the first and second ports (48A, 48C) have first and second nozzles (50A, 50C) with first and second nozzle openings (52A, 52C) for providing fluid communication between the annular channel and a spool, the first and second nozzle openings (52A, 52C) each having diameters smaller than the diameter of their respective port (48A, 48C), wherein, in a first axial position of the member the second nozzle opening is at least substantially obstructed by the second frusto-conical surface and the first nozzle opening is at least substantially unobstructed by the first frusto-conical surface, and in a second axial position of the member the first nozzle opening is at least substantially obstructed by the first frusto-conical surface and the second nozzle opening is at least substantially unobstructed by the second frusto-conical surface. a valve housing; a cavity formed in the valve housing and defining a longitudinal axis; and a member disposed in the cavity and axially-moveable therein, wherein the member comprises first and second cylindrical sections (32, 34) having a first radius (R1, R2), a central cylindrical section located between the first and second cylindrical sections (32, 34) and having a second radius smaller than the first radius (R1, R2), and first and second frusto-conical sections (37, 39) connecting the first and second sections (32, 34) to the central section and forming respective first and second frusto-conical surfaces (38, 40), wherein the member defines an annular channel radially between the member and the valve housing, and the annular channel is bounded by the first and second cylindrical sections (32, 34), and wherein the valve housing comprises a plurality of ports (48A, 48B, 48C), each forming a fluid passage through the valve housing in fluid communication with the annular channel, the plurality of ports (48A, 48B, 48C) comprising first and second ports (48A, 48C) each defining a diameter, the first and second ports (48A, 48C) have first and second nozzles (50A, 50C) with first and second nozzle openings (52A, 52C) for providing fluid communication between the annular channel and a spool, the first and second nozzle openings (52A, 52C) each having diameters smaller than the diameter of their respective port (48A, 48C), wherein, in a first axial position of the member the second nozzle opening is at least substantially obstructed by the second frusto-conical surface and the first nozzle opening is at least substantially unobstructed by the first frusto-conical surface, and in a second axial position of the member the first nozzle opening is at least substantially obstructed by the first frusto-conical surface and the second nozzle opening is at least substantially unobstructed by the second frusto-conical surface.