Features: The insulation puncture needle is very thin but hard enough, the diameter of needle is 0.7mm. You can use it to accurately pierces the outer of the cable for testing. Will not affect the integrity of the cable. The tip ensures good contact with the electrical connect, and the insulation of the pin prevents it from shorting with other wire. Antibreakage soft handles, copperneedle, manipulating test probes in test more sensitive and better, good quality and extremely wear resistant. It is fit for the connectings banana plug, post tie, can help your multimeter. You can use it to calculate electricity. The probe have inner diameter of 4mm and can be connectings to a standard plug. Specifications: Material:ABS Needle size: 0.7mm/0.03inch Package Includes: 10Pcs Multimeter Tester Needle note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color.