Handy, Quick and Easy For DTL, for TTL and for CMOS High Frequescy Response Instant Indication Memory Function How to use: RED clip to + terminal and BLACK clip to - terminal of the power source of the circuit under test. The supply should not 18V for Dc for TTL and DTL, set the upper select to the side marked "TIL" For CMOS, set the upper select to the side marked "CMOS", contact the probe pin to the point to be tested. The LEDs indicate its states: A) ALL LEDs OFF -High impedance B) RED LED ON - High (1) C) Green LED ON - low (0) D) Orange LED ON - for deteching and storing or level , set lower select to side marked first. Contact the probe pin to the poin to be tested. The LEDs indicate is basic Then set the lower select to side marked "", The orange LED light when any or level is detected. The direction, in comparison with basic, , cabe determined. After use, reset probe by setting the lower select to side marked "" Color: Black Material: ABS Package Contents: 1 * Logic Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.