1. Pulse Testing Method.
2. Polarity
   a. Pos. polarity :Green LED indicator with beep sound.
   b. Neg. polarity : Red LED indicator with no sound.
3. Sensor : ECM
4. Five selecting switches
   WF : suitable for the woofer.
   M & T : suitable for the midrange, tweeter & headphone.
   Ext.1 ~ Ext.3 : For connecting instruments.
5. Dim. :  28 ( L ) ¡¿ 9 ( H ) ¡¿ 21 ( D ) cm.