Sleeve (1) for a high- or medium-voltage power cable (120) having an inner conductor (130). The sleeve comprises (i) a tubular sleeve body (10) having an electrically conductive or semiconductive first axial electrode section (60), and (ii) a circuit board (30). The sleeve is radially expandable or shrinkable. It can be arranged radially outward of the inner conductor, such hat the first axial electrode section is radially separated from the inner conductor by at least an electrically insulating spacer layer (140). The circuit board is at least partially arranged radially outward of the sleeve body and comprises an electrical contact (100) which is electrically connected with the first axial electrode section.