Disclosed is apparatus (110) comprising a first device (120) adapted to be releasably operatively coupled to a second device (130). The second device comprises a detection coil (136) associated with a coupling arrangement (133) of the second device. The first device comprises a sensing coil (2206) arranged at a coupling region (123) of the first device, the coupling region being operatively associable with the coupling arrangement of the second device. The apparatus also has a circuit (125) connected to the sensing coil and configured to detect at least coupling of the first device to the second device through interaction of the detection coil with an electrical signal imparted upon the sensing coil.