Handy, Quick and Easy For DTL, TTL and CMOS High Frequescy Response Instant Indication Memory Function How to : 1. RED clip to + terminal and BLACK clip to - terminal of the source of the circuit under test. The supply voltage should not exceed 18V DC 2. For TTL and DTL, set the upper select switch to the side marked TIL For CMOS, set the upper select switch to the side marked CMOS, contact the probe pin to the to be tested. The LEDs will indicate logic states: A. ALL LEDs OFF -High impedance B. RED LED ON - High State (1) C. Green LED ON - low State (0) D. Orange LED ON - 3. For deteching and storing or level transition, set lower select switch to side marked first. Contact the probe pin to the poin to be tested. The LEDs will indicate is basic state. Then set the lower select switch to side marked , The orange LED will light when any or level transition is detected. The direction, in comparison with the original basic, state, cabe determined. After , reset logic probe by setting the lower select switch back to side marked Colour: white Material: plastic Size: 14 x 3cm Package Contents: 1 x Logic Probe Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.