Engineered to provide thorough, quantitative fit tests, our full line of specially modified facepiece assemblies offer quality construction and accurate responses. Each of our probed facepieces is equipped with a sampling line and a clothing clip to hold the sampling line. They also feature a built-in probe assembly, which feature solid brass probes. In our half-facepiece models, we attach the probe to the body of the respirator. Full-facepiece respirators are probed through the lens and sealed with a neoprene washer and brass fittings. For existing Ultravue® facepieces, our probed lenses come completely assembled with the same brass probe, sealing hardware and sampling line as the probed full facepieces.