5000mL complete Kriel Photochemical reactor includes a five-neck tapered flask with a #50 center neck, (2) 29/42 side necks, and (2) #7 Ace-Thred side necks, quartz immersion well, glass stopper, stirring shaft, stir bearing, and stir magnet. The reactor is most useful in prep-scale photolysis, and the tapered sides of the flask assure full submersion using either 509558006 or 50975483 immersion lamps within the supplied quartz immersion well, which allows for a 20% savings in reaction time over round bottom flasks. Additionally, the flat bottom design allows for immediate stirring with a magnetic stirrer, and mechanical stirring after only being 1/3 full.