The Lisle Corporation Flexible Back Probes, No. 65150, are made of flexible silicone which bends up to 180 degrees to access hard-to-reach areas. The probes are made for checking harness connectors and sensor wiring, and are fully insulated to provide added protection. These probes come with standard 4mm female banana plug connections and are for use up to 30V. The wire probe is 0.038” diameter.