Comparison : Item # QC-MAXI-350-R-24, CondenSyn MAXI 350 mm for Reflux
Item # QC-MAXI-450-R-24, CondenSyn MAXI 450 mm for Reflux
Item # QC-MAXI-350-D-24, CondenSyn MAXI 350 mm for Distillation
Item # QC-MAXI-450-D-24, CondenSyn MAXI 450 mm for Distillation