The digital AC voltage, current and frequency are displayed on the same meter at the same time. The meter does not need to add power supply and former. The meter comes with a 120A precision small former.<br> This inst ent is only suitable for pure AC 50-60HZ mains power supply. It cannot be used for square wave, inverter output, and sine wave circuits with modified sine waves, otherwise the inst ent will be permanently !<br> 120A former (hole diameter 15mm) can meet the national standard 21-25 square millimeter standard copper wire through.<br> Voltage: AC50-500V<br> Current: AC0-120A<br> Frequency: 10-99.9Hz<br> Hole size: 68x68mm (embedded installation)<br> Measurement accuracy: 1%±2 words<br> Colour:black<br> Material:ABS<br> Size:72 x 72 x 32mm<br> Package Contents:<br> 1 x measuring inst ent<br> Only the above package content, other products are not included.<br> 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.