Thin Williams/11.5B Screening Color-Coded Probe Thin Williams/11.5B Screening Color-Coded Probe PQOW11.5B6 Double-ended, color-coded probe. Ergonomic, Satin Steel™ handle. Thin Williams/Screening probe. Where to Buy x Category Dealer PartnersSales RepresentativeStrategic MarketsSchools RepresentativeAccutron™ Equipment Sales Zip Code Find RepresentativeReset Select a category, input a zip code and click on Find Representative, or explore the complete list here.