1. Puncture clips allow achieving the precise pressure required to puncture the insulation of various wire types and sizes. 2. The design is both cost-effective and convenient. It can be quickly removed to the puncture tip for any required sharpening, extending the life of the product and eliminating the need to completely replace the test clip as with other models on the market. 3. The red and black color-coded system provides quick circuit identification, and the bright yellow body is easy to locate in low light conditions. 4. The test clip offers further functionality with the 'in-line retention' feature. The test clips are attached to the leads, and the test leads can be removed from the clips for testing in another location. 5. Use: Attach it to the banana plug, and then the other end can be hooked onto the insulated wire. By turning the red or black end of the clip, the sharp needle pierces the insulation to make contact with the conductor. The puncture probe measures voltage with a voltmeter without cutting or stripping the outer layer of insulation. Color: Yellow + Red Material: Plastic Package Contents: 4 x Puncture Probe 2 x Banana Socket (Multimeter Lead) 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 to appear slightly different from the real thing. The measurement allowed error is +/- 1-3cm.