PECO PL-17 PROBE -FOR USE WITH PL-18 STUDS & TAGS Probe for use in stud & probe point operation Use with Peco studs (PL-18) to control turnouts & signals Wire apx40cm long, includes wiring information. For use when creating a traditional stud and probe control panel. Connect the studs to the point motors, and the probe to the power source. Also for use with diode matrix type panels.