The KCR20 near field probe group consists of three passive magnetic field probes with sizes from large to small. and an electric field probe. The probes have a relatively flat frequency response in the range of to 3GHz, which is used to measure the magnetic field during the development stage. The magnetic field probe is also sensitive in low frequency band. The diameter of the three probes is 20mm, 10mm and 5mm respectively. The probe with large diameter has high sensitivity but low directional resolution, while the corresponding probe with small diameter has low sensitivity but high directional resolution. In use, the probe with large size is usually used first to confirm the approximate area where the interference source is located, and then the probe with small diameter is switched to reduce the search scope to gradually identify the interference magnetic field source in the electronic module. Specification: Material: Metal Weight: 45g Size Chart: 120x25x14mm/4.72x0.98x0.55inch Package Includes: 4x Test Probe Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful on-line shopping!