A first connector part of a magnetic connector assembly for connecting an electrode for attachment to a subject's body to a connector of a medical device, said first connector part being configured to be connected to a second connector part such that an electrical signal may be transmitted therebetween, the first connector part comprising: a target comprising magnetisable material; a first connection surface, disposed on the target, arranged to be engaged with a corresponding second connection surface on a second connector part such that an electrical signal can be transmitted between the first connection surface and the second connection surface; and wherein the first connector part arranged such that, when exposed to a uniform magnetic field, the magnetic force experienced by a first area of the connection surface is substantially weaker than the magnetic force experienced by a second area of the connection surface, wherein the first area of the connection surface is located adjacent to an edge of the connection surface, and wherein one of the first and second connection surfaces (82, 38) comprises a protrusion arranged to engage with a corresponding recess on the other one of the first and second connection surfaces, wherein the engagement substantially prevents relative lateral movement between the first and second connection surfaces whilst permitting relative rotation thereof, wherein the rotation between the first connector part and the second connector part is permitted when both the said connector parts (70, 30) are engaged with respect to each other, characterized in that the target additionally comprises a non-magnetisable material, wherein the first area of the first connection surface corresponds to the part of the target which comprises a non-magnetisable material and the second area of the connection surface corresponds to the part of the target which comprises a magnetisable material. a target comprising magnetisable material; a first connection surface, disposed on the target, arranged to be engaged with a corresponding second connection surface on a second connector part such that an electrical signal can be transmitted between the first connection surface and the second connection surface; and wherein the first connector part arranged such that, when exposed to a uniform magnetic field, the magnetic force experienced by a first area of the connection surface is substantially weaker than the magnetic force experienced by a second area of the connection surface, wherein the first area of the connection surface is located adjacent to an edge of the connection surface, and wherein one of the first and second connection surfaces (82, 38) comprises a protrusion arranged to engage with a corresponding recess on the other one of the first and second connection surfaces, wherein the engagement substantially prevents relative lateral movement between the first and second connection surfaces whilst permitting relative rotation thereof, wherein the rotation between the first connector part and the second connector part is permitted when both the said connector parts (70, 30) are engaged with respect to each other, characterized in that the target additionally comprises a non-magnetisable material, wherein the first area of the first connection surface corresponds to the part of the target which comprises a non-magnetisable material and the second area of the connection surface corresponds to the part of the target which comprises a magnetisable material.