... Water Circulating Pump Working Temp. :(optional) -120~Room temp. Tank capacity (L):5,8,16,20,30,50,80 20L Cooling Water Circulating Pump ... 4.Scientific experiment equipments: molecular pump rotation evaporation meter, distillation, fermentation device, laser, metal 5.rapid prototyping device, vacuum coating ... 20L,30L,50L, 80L Low temperature Cooling Circulating Pump 20L Cooling Water Circulating Pump