Like the Vapor Pin^® barb extension or the Vapor Pin^® 1.5-inch extension, the Vapor Pin® sealing extension is placed beneath the Vapor Pin^® sampling device to minimize contact between soil gas and the hole in the slab. The sealing extension has the additional advantage of using a second Vapor Pin^® sleeve at the base of the slab. Depending on slab thickness, one or more Vapor Pin^® 1.5” extensions can be placed between the Vapor Pin^® sampling device and the Vapor Pin® sealing extension to extend the assembly to the bottom of the slab. Unlike most stainless steel products from Vapor Pin®, the sealing extension is not designed to be removed or reused.