PP. Versatile and inexpensive racks for common diameters test tubes. Sturdy construction, stackable. Test tube racks are made of PP (filled PP, density 1,2 g/cm3), will not float in waterbath. Alphanumerical positions for clear sample identification. Wide spaces between positions. Operating temperature -20 to 90°C. Autoclavable at 121°C. Racks are supplied in three-pieces for convenient and permanent assembly. Six sizes each available in four different colors.