The Phil’s Probes and Services 11" Phil's Electrical Piercing Probe was designed and tested by a technician for technicians. The probe pierces wires from 10 to 18 gauge and has five piecing pins to ensure good connection. The probe features a reach of 11" and is available in two other lengths: 15" and 6". Connect using a banana socket connection or an alligator clip right on the shaft just below the handle. The probe offers one-handed operation. Phil's Probe is to be used only on low voltage DC circuits such as 12V DC automotive system circuits.