Screw Top TubesGlass: Low Borosilicate or NeutralUniform Wall Thickness: 0.8mm to 1.2mmPP or Bakelite Cap AvailableFlat or Round BottomO.D. 10, 12, 13, 15, 16, 18, 20, 22 and 25mmLength: As requiredApprox. Volume: 5ml to 100ml