We use peroxide-cured silicone tubing with the Vapor Pin® sampling device. Our studies indicate that the tubing does not affect the sample results. The tubing surrounds the bottom half of the pin forming the seal between the 5/8-inch hole and the Vapor Pin® sampling device. Sub-slab vapors are exposed to very little of the silicone tubing. Side-by-side comparisons with conventional sample points indicate that no vapors are added to or subtracted from soil gas by the silicone sleeve. Additionally, Cox-Colvin screens the silicone tubing upon arrival to ensure that sleeves with elevated levels of VOCs are not sent to customers.