Compact Monitor Systems - The JBL 2450CM made exclusively for Compact Monitor Systems, which allows a light weight Neodymium 2" driver to accept the JBL D16R2482 ~ a 4" edgewound aluminum ribbon
Amazon.com: SS Audio Diaphragm Compatible with JBL 2446, 2447, 2450, 2451, 16 Ohm, D-2450-16 : Electronics