An adjustable socket system comprising: a base; a plurality of longitudinal supports comprising first and second supports (904A, 904B) connected to the base and extending along a longitudinal axis of the adjustable socket system; a plurality of shell components comprising a first shell component connected to the first support and a second shell component connected to the second support and at least in part defining a receiving volume adapted to receive a residual limb, the adjustable socket system movable between an open configuration in which at least one of the first and second shell components (906A, 906B) are moved radially outward relative to the longitudinal axis to loosen a fit of the adjustable socket system, and a closed configuration in which at least one of the first and second shell components (904A, 904B) are moved radially inward relative to the open configuration to secure the fit of the adjustable socket system on the residual limb; and a tightening system arranged to selectively move the adjustable socket system between the open and closed configurations, the tightening system including a tensioning unit, means rotatable about a rotation axis, and at least one tensioning element operatively coupled to said means, wherein the tensioning unit includes at least one movable connection point, and the at least one tensioning element is operatively coupled to said means via the at least one movable connection point and to at least one of the plurality of shell components via at least one control point, wherein rotation of said means about the rotation axis from an off position to an on position displaces both of the at least one movable connection point, and the at least one tensioning element relative to the at least one control point to tension the at least one tensioning element and to move the adjustable socket system to the closed configuration, characterized in that said means comprise a handle defining a momentum arm rotatable about the rotation axis, and the at least one movable connection point is located and protected between the second support and the second shell component, wherein rotation of the handle about the rotation axis from the off position to the on position displaces the at least one movable connection point between the second support and the second shell component. a base; a plurality of longitudinal supports comprising first and second supports (904A, 904B) connected to the base and extending along a longitudinal axis of the adjustable socket system; a plurality of shell components comprising a first shell component connected to the first support and a second shell component connected to the second support and at least in part defining a receiving volume adapted to receive a residual limb, the adjustable socket system movable between an open configuration in which at least one of the first and second shell components (906A, 906B) are moved radially outward relative to the longitudinal axis to loosen a fit of the adjustable socket system, and a closed configuration in which at least one of the first and second shell components (904A, 904B) are moved radially inward relative to the open configuration to secure the fit of the adjustable socket system on the residual limb; and a tightening system arranged to selectively move the adjustable socket system between the open and closed configurations, the tightening system including a tensioning unit, means rotatable about a rotation axis, and at least one tensioning element operatively coupled to said means, wherein the tensioning unit includes at least one movable connection point, and the at least one tensioning element is operatively coupled to said means via the at least one movable connection point and to at least one of the plurality of shell components via at least one control point, wherein rotation of said means about the rotation axis from an off position to an on position displaces both of the at least one movable connection point, and the at least one tensioning element relative to the at least one control point to tension the at least one tensioning element and to move the adjustable socket system to the closed configuration, characterized in that said means comprise a handle defining a momentum arm rotatable about the rotation axis, and the at least one movable connection point is located and protected between the second support and the second shell component, wherein rotation of the handle about the rotation axis from the off position to the on position displaces the at least one movable connection point between the second support and the second shell component.