The PCB with the coil mounted in the coil housing. The enclosure is made of the same plastic as the EHU and painted the same way. The PCB is attached to the enclosure only by the brass terminal screws (4 for the control cable and 1 for ground) and 2 of the screws on the RF connector. Nothing else is used to secure the PCB and coil inside the enclosure. The coil form is a tight fit and when the cover is installed, the cover presses against the 5 small rubber feet on the coil (used to keep the winding in place and properly separated). This provides some additional mechanical support.