A cochlear implant system includes a subcutaneous housing which includes a main body and a bottom cover secured to the main body. A central cavity in a center of the subcutaneous housing is formed by a portion of an outer surface of the main body. A magnet is removably inserted into the central cavity and includes a cylindrical body with a central axis aligned with a removal axis of the central cavity, a groove extending circumferentially around the cylindrical body, and a top surface. The top surface includes an outer edge, a plurality of ribs extending radially farther than the outer edge, and a plurality of abutments extending radially farther than the ribs. Further, a compressive ring is seated in the groove of the cylindrical body and engages under a ledge in the central cavity when the magnet is inserted into the central cavity and biases the magnet against removal from the central cavity.