A photo of the secondary coil by itself is shown here. The magnetic attractor is the piece in the center. The secondary coil is very thin and flat, to allow it to be built onto the back housing of a handheld device. The evaluation board assembly for the RX side is set up so that the end user can install their desired battery in the space of the housing for test purposes. Note that like the TX coil, there is a shield layer which is integrated with the receive coil as a single subassembly. When the receiver device is placed on the transmit pad, the unshielded sides of the coils face each other, with the shield layers on the outside of the “sandwich” to contain any uncoupled field lines.