An inductor coil, comprising: a first component comprising a first base portion and a first cylindrical core portion; a second component comprising a second base portion and a second cylindrical core portion; and a length of conductor; wherein, the first cylindrical core portion is located adjacent to the second cylindrical core portion; wherein, a core is formed from the first cylindrical core portion and the second cylindrical core portion; wherein the core is located along a first portion of a central axis and a second portion of the central axis; wherein, along a third portion of the central axis the first cylindrical core portion is spaced from the second cylindrical core portion to form a gap (20, 30) in the core, wherein the third portion of the central axis is between the first portion of the central axis and the second portion of the central axis; wherein, a first part of the length of conductor is located around the first portion of the central axis, located around the second portion of the central axis, and located around the third portion of the central axis to form a plurality of turns of conductor around the core and the gap in the core; wherein each turn of conductor of the plurality of turns of conductor has an inner part of the conductor spaced at least one distance from the central axis in a direction perpendicular to the central axis, wherein the inner part of the conductor of two or more turns of the conductor located around the first portion of the central axis and/or located around the second portion of the central axis are spaced from the central axis by at least one first distance, and wherein the inner part of the conductor of one or more turns of the conductor located around the third portion of the central axis is spaced from the central axis by at least one second distance greater than the at least one first distance; and characterized in that at least one section of the first part of the length of conductor between the first base portion and the second base portion is compressed in the direction of the central axis between and by the first base portion and the second base portion. a first component comprising a first base portion and a first cylindrical core portion; a second component comprising a second base portion and a second cylindrical core portion; and a length of conductor; wherein, the first cylindrical core portion is located adjacent to the second cylindrical core portion; wherein, a core is formed from the first cylindrical core portion and the second cylindrical core portion; wherein the core is located along a first portion of a central axis and a second portion of the central axis; wherein, along a third portion of the central axis the first cylindrical core portion is spaced from the second cylindrical core portion to form a gap (20, 30) in the core, wherein the third portion of the central axis is between the first portion of the central axis and the second portion of the central axis; wherein, a first part of the length of conductor is located around the first portion of the central axis, located around the second portion of the central axis, and located around the third portion of the central axis to form a plurality of turns of conductor around the core and the gap in the core; wherein each turn of conductor of the plurality of turns of conductor has an inner part of the conductor spaced at least one distance from the central axis in a direction perpendicular to the central axis, wherein the inner part of the conductor of two or more turns of the conductor located around the first portion of the central axis and/or located around the second portion of the central axis are spaced from the central axis by at least one first distance, and wherein the inner part of the conductor of one or more turns of the conductor located around the third portion of the central axis is spaced from the central axis by at least one second distance greater than the at least one first distance;