A system for electrical coupling, comprising: a treatment apparatus having a proximal end and a distal end; an elongate power cable having a proximal end configured for coupling to a power source, and a distal end; a first coupler portion at the distal end of the power cable, the first coupler portion having at least a first electrical contact and at least one first magnetic portion; a second coupler portion at the proximal end of the treatment apparatus, the second coupler portion having at least a second electrical contact and at least one second magnetic portion, wherein the first and second magnetic portions (60, 72) are magnetically attractable to each other; and a sleeve having a proximal end and a distal end, the sleeve being configured to cover at least a portion of the first and second coupler portions (50, 63) when the first and second coupler portions (50, 63) are coupled to one another, wherein the sleeve comprises a retracted state in which the sleeve covers only portions of at least one of the treatment apparatus and the second coupler portion, and an extended state in which the sleeve covers the first and second coupler portions (50, 63) and at least a portion of the elongate power cable; wherein the magnetic attraction between the at least one first magnetic portion and the at least one second magnetic portion (60, 72) draws the first and second coupler portions (50, 63) to one another and causes the first and second coupler portions (50, 63) to releasably couple and self align to one another when the first and second coupler portions (50, 63) are brought into close proximity to one another, such that the first electrical contact makes electrical connection with the second electrical contact, thereby coupling the distal end of the elongate power cable to the proximal end of the treatment apparatus. a treatment apparatus having a proximal end and a distal end; an elongate power cable having a proximal end configured for coupling to a power source, and a distal end; a first coupler portion at the distal end of the power cable, the first coupler portion having at least a first electrical contact and at least one first magnetic portion; a second coupler portion at the proximal end of the treatment apparatus, the second coupler portion having at least a second electrical contact and at least one second magnetic portion, wherein the first and second magnetic portions (60, 72) are magnetically attractable to each other; and a sleeve having a proximal end and a distal end, the sleeve being configured to cover at least a portion of the first and second coupler portions (50, 63) when the first and second coupler portions (50, 63) are coupled to one another, wherein the sleeve comprises a retracted state in which the sleeve covers only portions of at least one of the treatment apparatus and the second coupler portion, and an extended state in which the sleeve covers the first and second coupler portions (50, 63) and at least a portion of the elongate power cable; wherein the magnetic attraction between the at least one first magnetic portion and the at least one second magnetic portion (60, 72) draws the first and second coupler portions (50, 63) to one another and causes the first and second coupler portions (50, 63) to releasably couple and self align to one another when the first and second coupler portions (50, 63) are brought into close proximity to one another, such that the first electrical contact makes electrical connection with the second electrical contact, thereby coupling the distal end of the elongate power cable to the proximal end of the treatment apparatus.