Individual drive tubes for use with the density drive sampler. Tubes are available for 3" (76.2mm) x 2.75" (69.9mm) length, (3" x 0.01 ft3) for use with the GAM-1686 drive sampler. Individual drive tubes for use with the 4" sampler GAM-1697 are available 4" (101.6mm) x 5" (127mm) length, (4" x 0.033 ft3).