The wlx proi is an easy to use and affordable wireless audio system combining the wlt pro transmitter with the wr pro camera mount receiver the wlt pro combines the wm pro body pack transmitter with the ex 503 electret condenser omni directional lavalier microphone this is the standard 2 frequency switchable 169445mhz and 170245mhz body pack transmitter for all ldquoprordquo series receivers it uses a single 9v alkaline battery and comes with a belt clip and is compatible with smar