Home / Products tagged “Nextteq G” Nextteq G Nextteq Gasoline Detector Tubes, 0.01 – 0.6%, pk/10 $85.00 Ships directly from the manufacturer, shipping times may vary. Nextteq General Hydrocarbons Detector Tubes, 50 – 1,400 ppm, pk/10 $80.00 Ships directly from the manufacturer, shipping times may vary.